Hyperthyroidism, Graves Disease, Symptoms, Diagnosis, Wolff Chaikoff Effect, Medicine Lecture, USMLE

okay in our video series of Endocrinology lectures in this video we are going to talk about hyperthyroidism we are going to discuss the presentation the causes the diagnosis and the treatment of hyperthyroidism in detail a 32-year-old anxious lady comes to your clinic complaining of weight loss doctor I have been losing weight for the last few months doctor I have been having this chronic diarrhea diarrhea all the time I have been taking many treatments and many medications to stop the diarrhea but it is not resolve ing doctor I feel that my heart is pounding in the chest I have these palpitations all the time doctor I feel that I am sweaty while the others are feeling cold I feel that my body is very warm when you examine the patient there is a steering look in the eyes like this there is fine Tremor present in the hands she complains of anxiety she complains of being in stress all the time this is a classical presentation of graves disease which is a form of hyperthyroidism what is hyperthyroidism how do you diagnose it today we'll discuss that hyperthyroidism is a condition characterized by over production of the thyroid hormones by the thyroid gland thyroid gland is a gland that is present in our neck in front of the trachea that produces thyroid hormones and as we discussed in our video on hypothyroidism these thyroid hormones are the few of the body they run the Machinery the Machinery is the body and the fuel is the thyroid hormones and when there is more fuel the body is on fire so literally the every organ of the body is running very fast is hyperfunctioning that is what is happening in hyper thyroidism basically where does these thyroid hormones come from hypothalamus in the brain signals the anterior pitutary through thid releasing hormone to secrete a hormone called as thyroid stimulating hormone so signal from hypothalamus releases thyroid releasing hormone thyroid releasing hormone acts on anterior pitutary and releases thyroid stimulating hormone thyroid stimulating hormone acts on the thyroid gland present in our neck and that thyroid gland then produces thyroid hormones th these thyroid hormones include T3 and T4 and remember T3 is the active form of thyroid hormone this T4 gets converted to T3 in the peripheral tissues and T3 is the more active form of the thyroid hormones and in hyper thyroidism there is excess of these thyroid hormones now before going ahead you must be clear about two terms hyper thyroidism and you will also have heard about thyrotoxicosis what is the difference between these two remember thyrotoxicosis is inappropriately high levels of circulating thyroid hormones irrespective of the cause irrespective of the source wherever these thyroid hormones are coming from maybe these are some cancers present in the ovaries maybe it's the pitutary adoma maybe it's from the direct thyroid gland so irrespective of the source maybe the patient is taking thyroid hormones from outside Libo thyroxin tablets so irrespective of the source of these thyroid hormones if the patient is having symptoms of hyperthyroidism that is called as thyrotoxicosis the inappropriately high levels of circulating thyroid hormones irrespective of the cause but when these thy hormones are specifically being secreted by the thyroid gland that is called as hyper thyroidism so there is a difference between thyrotoxicosis and hyperthyroidism now what are the causes of hyperthyroidism remember the most common and the most important cause in 80% of the cases is Graves disease second cause is toxic multinodular goer third cause is thyroiditis we'll discuss each of these causes in detail now other than that iodine induced hyperthyroidism is also a cause of hyperthyroidism other than that Struma ovar is a very important cause and that is highly tested in exams they will ask you the patient is having some ovarian tumor and that ovarian mass is causing the symptoms of hyperthyroidism and they would expect you to know that this patient is having ovarian teratoma that is called as Struma ovary and Struma ovary contains thyroid cells and that ovarian tumor secretes these thyroid hormones and causes symptoms of thyrotoxicosis other than that pitutary adenoma there can be a mass present in the pitutary gland that secretes thyroid stimulating hormone and makes the thyroid gland secrete more thyroid hormones other than that a commonly tested point in exams is also HRA form mole they would give you a scenario that a patient is pregnant and that patient is having signs and symptoms of hyperthyroidism when you perform the ultrasound scan of that patient you would see that that patient is not having any pregnancy that patient is having hydraform Mo in the uterus and that hydraform Mo in the uterus mimics pregnancy and that Hydro form Mo secretes excess amount of beta HCG and that beta HCG mimics it resembles TSH and stimulates the thyroid gland to secrete thyroid hormones so htic form mole is a cause of hyperthyroidism radiation can damage the thyroid gland and release the preformed thyroid hormones so these are some causes but now we will go into the most important causes of hyperthyroidism and that is the graves disease Graves disease is the most common cause of hyperthyroidism and it is autoimmune condition most common in middle- age female like other autoimmune condition it is also common in middle-age females basically what happens in Graves disease is that antibodies are formed and those antibodies bind to the TSH receptors present on the thyroid gland these antibodies bind to the TSH receptors and they stimulate the TSH receptors and they cause secretions of loads and loads of thyroid hormones from the thyroid gland so these are actually TSH receptor Auto antibodies and they stimulate the thyroid gland to an extent that they cause excess production of thyroid hormones from the thyroid gland that results in the graves disease these antibodies include TSH receptor antibody T R A these also you will also hear about antibody called as lats long acting thyroid stimulating antibodies so these are basically antibodies and they stimulate the thyroid gland to produce excess amount of thyroid hormones in the body now when you have a patient with hyperthyroidism a test that you perform in these patients is called as radioactive iodine skin now when you perform radioactive iodine scan in a patient with Graves disease what you see is that there is diffuse uptake of radioactive iodine by the thyroid gland because whole of the thyroid gland is hyperactive hyper stimulated and whole of the thyroid gland will take up radioactive iodine and it will light up the picture so this is a picture showing a normal thyroid skin where there is uptake of radioactive iodine and this is a patient suffering from graves disease and look at the iodine uptake by the patient with Graves disease look at the thyroid gland the thyroid gland is hyperactive and all of it is taking excess amount of radioactive iodine so that is how you test a patient with gra disease other than that when you examine the patient with Graves disease the thyroid gland is diffusely enlarged and sometimes the patient with Graves disease can also have a goer and that will be a painless goer the patient will not be having pain the thyroid gland will be smooth on examination smooth and enlarged thyroid gland is seen in patients with Graves disease the thyroid gland is painless now there are certain signs if these signs are present then the cause of hyperthyroidism is most likely Graves disease if you see opthalmopathy signs like lid retraction lid leg if you see opthalmopathy opthalmopathy is seen in Graves disease the cause of hyperthyroidism is Graves disease if there is opthalmopathy if you see preal miedema it's very likely that it is due to Graves disease so Graves disease causes of theopathy and pretibial meadema while the other causes of hyperthyroidism do not cause opthalmopathy now that was all about the graves disease coming to toxic multinodular gerer in the toxic multinodular guer what happens is it is commonly seen in patients greater than 50 years of age Graves disease is seen in patients with 20 to 30 years of age in these patients what you see is that there will be a enlarged goer and when you examine the goiter it will be of a nodular pattern in Graves disease the goer can be smooth in toxic multinodular goer there will be hyperthyroidism and the goer will be nodular basically it happens due to Chronic iodine deficiency in areas where there is chronic iodine deficiency the TSH will stimulate the thyroid gland and thyroid gland would get enlarged but now when these patients take iodine their a thyroid gland is very enlarged the tissue is enlarged and it will take up small amount of iodine and it will produce excess amount of thyroid hormones so when these patients get iodine from their diet their thyroid gland is enlarged and thyroid gland will take up all of the iodine and it will produce excess amount of thyroid hormones so initially the thing starts with chronic iodine deficiency they develop goer and when they get iodine in the diet the tissue is enlarged and that tissue will produce excess amount of thyroid hormones when you examine the goer it will be nodular and it will be painless and when you perform radio iodine scan you will see multiple FY of upake because there are these nodules that will take up the iodine and produce excess amount of thyroid hormones so this is a normal thyroid scan and when you perform thyroid scan in toxic multinodular G this is the picture that you see these are the nodules that are producing excess amount of thyroid hormones coming to the third cause thyroiditis what happens in thyroiditis is that thy thyroiditis is actually destruction of the thyroid gland now we discussed thyroiditis in hypothyroidism and we are also discussing it in hyper thyroidism basically what happens in thyroiditis is that there is destruction of the thyroid gland due to any infection due to immune mediated reaction so there can be destruction of the thyroid gland either due to infection or due to immun mediated uh reaction but that destruction of the thyroid gland will release preformed thyroid hormones in the body and there will be excessive surge of thyroid hormones in the blood that will cause the signs and symptoms of thyrotoxicosis and hyperthyroidism but after that signs and symptoms of hyperthyroidism that patient will will ultimately go into hypothyroidism because the thyroid gland is damaged so initially in the patients with thyroiditis there will be hyper thyroidism but after some time the patients will develop hypothyroidism due to destruction of the gland so that is a cause of hypo as well as hyperthyroidism in thyroiditis there is transient thyrotoxicosis followed by features of hypothyroidism when you perform the radio isotope scan since there is destruction of the thyroid gland and gland cannot take up the radioactive iodine so there will be reduced uptake in patients with thyroiditis now there are certain antibodies that are also involved in the pathogenesis of thyroiditis like antithyroid peroxidase antibodies if you perform thyroid skin in these patients there will be reduced uptake because there is destruction of the thyroid gland so the thyroiditis will show reduced uptake thyroiditis is divided into two types Subacute granulatus thyroiditis also called as dequin thyroiditis where there is an infection in the the body and that infection destroys the thyroid gland and releases thyroid hormones so viral infection microbacterial infection can cause Subacute glomus thyroiditis and the thyroid gland on examination is painful remember very important Point Subacute lymphocytic thyroiditis also called as silent thyroiditis where the thyroid gland is painless so the difference between these both is that in Subacute gratus thyroiditis the thyroid gland will be painful but in Subacute lymphocytic iratus it is silent it is painless it is caused by postpartum right after giving birth to the baby patient develops signs of hyper thyroidism because of the destruction of the thyroid gland that is immune mediated destruction autoimmune destruction of the thyroid gland certain drugs can cause thyroiditis like amidone amidone can cause hyper thyroidism as well as the hypothyroidism lithium can cause Subacute lymphocytic thyroiditis and thyroid gland is painless now coming to some really important and interesting phenomenas that you will be tested about in exam many times Jord based of phenomena and wolf chof effect what happens in Jord baso phenomena is that there is iodine induced hyperthyroidism iodine induced hyperthyroidism occurs in patients that are living in areas where there is low amount of iodine in the nutrition people living in areas where there is low amount of iodine in the nutrition their thyroid gland get accustomed to low amount of iodine in the nutrition and it produces thyroid hormones from that small little amount of iodine that is it is getting from the nutrition so their thyroid gland will produce IOD thyroid hormones from the iodine that it is getting but their receptors are upregulated to take up that small little amount of iodine that is being absorbed from the nutrition when these patients living in the areas where there is low iodine and their thyroid glands with upregulated receptors for the uptake of iodine when they come to the areas where there is increased iodine in the diet people taking iodized salts when they take up these type of salts and these type of nutrition with excess amount of iodine their thyroid hormone their thyroid gland takes up all the iodine and it is very happy that now I am getting loads of iodine that I did not use to get before so it starts taking up more and more iodine and it starts producing thyroid hormones resulting in iodine induced hyper thyroidism that is called as Jord based phenomena and it occurs in people living in iodine deficient areas where the thyroid gland is accustomed to small little amount of th iodine in diet but when they come to areas where there is increased iodine in the diet they their thyroid gland takes up all the iodine and start producing excess amount of thyroid hormones that is called as jbas phenomena now coming to a very interesting phenomena called as Wulf chof effect wolf chof effect is a very important and interesting phenomena basically if you have seen the season on Netflix uh called as Chernobyl it has it is a very interesting season with five to six episode in which there is explosion of a nuclear reactor in the city of Russia called as Chernobyl now when the explosion of the nuclear reactor takes place there is radiations all around all the water is having radiation everything is having radiation and if you have seen That season you would see that the characters in that season are taking potassium iodide tablets and they tell each other that take up this potassium iodide tablets it will uh protect your thyroid gland from the radioactive iodine why does that happen and how does that happen basically if you take excess amount of potassium iodide your thyroid gland will be like where is this excess amount of IOD coming from and it will stop the uptake of iodine it will stop the uptake of iodine due to excess amount of iodine present in the blood therefore the radioactive iodine that is present in the water and the nutrition now that cannot be absorbed by the thyroid gland because the thyroid gland is amazed and thyroid gland does not want excess amount of iodine so it is a phenomena that is opposite to JW Bas phenomena J baso phenomena occurred in people that that were living in iodine deficient area wolf chof effect is not like that wolf CH of effects occurs in common people having normal amounts of iodine in the nutrition but when they take excess amount of iodine from outside their thyroid GL stops the uptake of iodine from the diet and it stops the radioactive iodine from getting in the thyroid land so that is called as wolf CH of effects and that's why these characters were Tak taking potassium iodide from the uh from outside to prevent their glands from taking up radioactive iodine so that is called as wolf chof effect reduction in the thyroid hormone synthesis caused by ingestion of large amount of iodine so that is called as wolf chov effect hyperthyroidism is more common in females as compared to males 5 rao1 Graves disease commonly affecting 20 to 30 years of age toxic adoma 30 to 50 years of age and toxic multi nodular guer the incidence is more common in patients with greater than 50 years of age now coming to clinical signs and symptoms of hyperthyroidism remember thyroid hormones are the fuel of the body and when you give excess fuel to the body the body will be on fire the each and every organ will be hyperfunctioning there will be excessive heat production heat intolerance excessive sweating to dissipate that heat off from the body because the body is hyper functioning each and every organ is hyper functioning and producing excess amount of heat there will be weight loss it will burn the fat there will be frequent ball movement the git movement will be rapid and there will be diarrhea in these patient weakness and fatigue due to all the uh overwork that body is going through now coming to the eye signs eye signs is are seen in patients with Graves disease what you see is that there is lid lag basically when person normally looks down the eyelid would also go down but in patients with Graves of theopathy when they look down the eyelid does not go downward because because of the excessive spasm lid retraction that is present in patients with Graves disease lid retraction or steering look now normally the dark part of our eye the iris of our eye is actually covered upper upper part is covered by the eyelid but in patients with gves opthalmopathy their eyelid retracts and when their eyelid retracts the white part of the uh eye is also visible above the iris so you you will have a steering look in these patient look at the retraction of the eyelid and the white part is visible above the iris white part is visible above the iris Graves opthalmopathy can involve the retroorbital areas as well and there is edema of the periorbital tissue that pushes the eyes outward so there is Graves opthalmopathy and look at the edema of the periorbital area periorbital muscles there is Ive deposition of glycos aminoglycan and hyaluronic acid and these gags attract water and they cause severe edema these patients cannot even move their eyes laterally properly in the later stages and sometimes it can even involve the optic nerve it can compress the optic nerve and compression of the optic nerve results in eventual blindness in patients with Graves of theopathy in cardiovascular system the heart would be overworked when the heart is overworked these patients will experience techic cardia pulpit irregular pulse and remember atal fibrillation huge Association of atal fibrillation with hyperthyroidism hyperthyroidism will make the heart work more and more and more and then the Atria will go into atal fibrillation so in patients with atal fibrillation always look for hyperthyroidism and patients with hyperthyroidism do ECG and look for atal fibrillation hypertension widen and pulse pressure bounding pulse in these patients high volume pulse you will see High volume pulse in these patients and there when you check the blood pressure the systolic pressures will be high there will be a wide pulse pressure thyrotoxicosis induced card in the later stages they would go into heart failure chest pain due to overworked heart in the muscular skeletal when you examine their hands they will be having fine Tremors in their hands when you place a paper it will become more visible there will be hyperthyroid myopathy the proximal muscles are extremely damaged in patients with hyper thyroidism remember proximal muscle myopathy is also present in hypothyroidism but it is also seen in hyperthyroidism and the differentiating factor as we discussed in our previous video as well that Serum creatinin kyese is elevated in hypothyroid myopathy but it is normal in hyperthyroid myopathy so hypothyroidism the myopathy elevates the CK levels but in hyperthyroidism the CK levels are normal osteoporosis it destroys the bone so U osteoporosis it destroys the bone and there is excessive sweating due to excessive heat production in the body in the endocrine females develop olom manoria a manoria in ovulatory Cycles infertility dysfunctional uterine bleeding disturbance in the normal uterine Cycles males experience gynecomastia erectile dysfunction and there is hyperglycemia in patients with hyperthyroidism on the skin especially in patients with uh GES disease you will see pre tipal miedema there will be infiltrative dermopathy there is basically excessive deposition of the glycos amino glycans in the pretibial area now remember we also discussed about miedema in hypothyroidism but miedema in hypothyroidism involves all of the body but in patients with Graves disease meadema occurs specifically in the pretibial area so this is basically glycos aminoglycan deposition and this is a picture showing pre TBL magida while hypothyroidism is the all of the body that is involved in hypothyroidism enois separation of the nails from the nail plate thyroid acopy nail clubbing is also seen in patients with hypothyroidism that is called as thyroid acopy now if you see preal magido opthalmopathy enois thyroid acopy this is Graves disease neuros psychiatric symptoms excessive brain function when you think more you get more anxious right Restless insomnia hyper reflexia on examination patients with grave disease will have diffused smooth non tender goer and there might be present an audible Brew in the superior poles seen in Graves disease now coming to the investigations of hyperthyroidism remember hypothalamus produces thyroid releasing hormone that acts on the anterior pitutary anterior pitutary secretes thyroid stimulating hormone that acts on the thyroid gland to produce thyroid hormones so you have to test the T3 T4 levels as well as the the TSH levels and T3 T4 levels will be high and TSH levels will be low especially where there is thyroid gland producing excess amount of thyroid hormones sometime it can also happen that there can be a pitutary adenoma mass in the pitutary gland that secretes excess amount of TSH and TSH will be elevated with an elevated T3 T4 so if the TSH is also elevated it means there is pitutary adoma if the TSH is low it is most likely Graves disease so in a PTI with hyperthyroidism you perform the thyroid function test you check the TSH level the TSH level is low and total T3 and free T4 is high it means that the patient is having overal hypothyroidism thyroid gland is producing excess amount of thyroid hormones if you perform the TSH level and TSH level is high with a total T3 elevated as well as a free T4 elevation this means that that patient is having a pitutary adenoma a mass in the pitutary gland that pitutary denoma is producing thyroid hormones and you need to perform MRI of the pitutary gland because excess TSH indicates that there is a mass in the pitutary gland you perform the MRI and you see a mass like this a mass like this this means that there is a mass producing TSH that is stimulating the thyroid gland to produce excess amount of thyroid hormones there can be another scenario where when you perform the TSH levels the TSH levels are low but the T3 and T4 levels are normal what does that mean that means that previously there was a certain amount of TSH that stimulated the thyroid gland to produce thyroid hormones but now the pitutary has to work Less on the thyroid gland and has to produce less amount of TSH to produce the same amount of thyroid hormones it means that the thyroid gland is overactive that thyroid gland does not need stimulation from the pitutary gland and it can produce thyroid hormone all by itself this is danger sign this means that that uh thyroid gland is overactive and it does not need stimulation from the pitri TSH is low and T3 T4 are normal it means that that patient is ultimately going to hyperthyroidism so it is called as subclinical hyper thyroidism just like subclinical hypothyroidism there is subclinical hyperthyroidism as well where the TSH stimulation uh is not needed for the T3 T4 production and it means that that patient will ultimately go into hyperthyroidism overt hyperthyroidism now if you have a female patient with hyperthyroidism low TS and increased T3 T4 or normal T3 T4 a good thing to do is to perform beta HCG levels in a in female that is of childbearing age you should perform beta HCG level because sometimes there can be a corio carcinoma hydraform mole that can that is producing excess amount of beta HCG and resulting in stimulation of the thyroid gland you perform beta HCG level and you rule out gestational thyro toxicosis it is not applicable in all cases only in specific patients that are having pregnancy you check the beta HCG levels to rule out that whether it is gestational thyrotoxicosis or not other than that you look for the signs of graves disease you look for opthalmopathy pretibial miedema acopy and clubbing if you find these most likely this is Graves disease if these are present this is Graves disease and then you the next test you perform is you check the antibodies antithyroid receptor stimulating antibodies if these are absent it means that something is wrong with the thyroid gland because it is producing excess thyroid hormones and TSH is low now you need to perform the thyroid scan that we discussed about you perform the radioactive iodine scan of the thyroid gland and then if there is diffuse uptake that is Graves disease if there is nodular uptake there is one toxic adenoma that is producing it if there are multi nodules and it means that there is multinodular G I have talked about thyroid nodule workup in detail in my video on thyroid nodule workup the link of that video is given in the description below if there is no uptake now you should know what can cause no uptake it's thyroiditis there is destruction of the thyroid gland with hyperthyroidism Hashimoto thyroiditis you perform thyroid peroxidase antibodies anti thyro globin antibody now would you be thinking that Hashimoto thyroiditis is a cause of hypothyroidism it's a thyroiditis initially it would cause hyper thyroidism and later it will develop into full-blown hypothyroidism thyroiditis exogenous thyroid hormone use patients taking thyroid thyroid hormone in excess maybe a patient was having hypothyroidism for which thyroid hormone was prescribed Leo thyroxin was prescribed but that Lio thyroxin dose is higher therefore it is causing the symptoms of hyperthyroidism serum cholesterol level were elevated in hypothyroidism serum cholesterol level are low in hyperthyroidism ECG must look for atal fibrillation most commonly you would see sinus techic cardia in these patients thyroid ultrasound is performed to look for thyroid nodule and if you find the thyroid nodule you go for a FY thyroid nodule workup has been explained in detail in my video on thyroid nodule workup so this was all about the causes the diagnosis the presentation of hyperthyroidism in the next video we'll be discussing in detail about the treatment of hyperthyroidism how a patient of hyperthyroidism would present to you and how would you treat that patient so make sure to watch my next video on the treatment of hyperthyroidism in summary we talked about what is hyperthyroidism difference between hyperthyroidism and thyrotoxicosis Graves disease being the most common one iodine induced hyperthyroidism stroma ovary pitutary adenoma hydraform mole Graves disease look for the antibodies diffuse uptake on the scan pretibial mieda of theopathy and Graves disease toxic multinodular gter multiple FY on thyroid skin uh thyroiditis we discussed that how there is reduced uptake and sometimes the antibodies can be positive initially thyrotoxicosis later on there will be hypothyroidism decreased uptake on the thyroid skan then we discussed what is iodine induced hypothyroidism JW based or phenomena people living in iodine deficient area go to a area with more iodine develop hyperthyroidism uh then we discussed wolf chof effect with the story of Shob we discussed what is the epidemiology and what are the age ranges affected in the different types of hyperthyroidism the clinical features the symptoms in the eye the LD leg the lad retraction the graves opthalmopathy cardiovascular signs and symptom AP being the most common one in the hyper thyroid myopathy the CK levels are normal in endocrine abnormal menes pretibial miedema thyroid acopy seen in Graves disease neuros psychiatric symptoms and then we discussed the workup of um hyper thyroidism and if the TSH is high it is pitutary adenoma if the TSH is low and the thyroid hormones are normal subclinical hypothyroidism root tech for beta HCG in patients that are pregnant signs of graves disease are seen in these patients then you perform radioactive iodine scan where there are no signs of hyperthyroidism and then you perform certain other tests as well if you likeed my video please click on the Subscribe button and make sure to watch my next video on the treatment of hyperthyroid ISM I have discussed ECG Series in detail I have talked about emergency medicine in detail there are different playlists present on my channel make sure to check those playlists out thank you very much

Channel: MedNerd - Dr. Waqas Fazal

Views: 14,315

Keywords: hyperthyroidism, hyperthyroidism causes, hyperthyroidism vs thyrotoxicosis, hyperthyroidism diagnosis, hyperthyroidism investigations, hyperthyroidism graves disease, graves disease, wolff chaikoff effect, jod basedow phenomena, diagnosis of graves disease, thyrotoxicosis, struma ovari, graves opthalmopathy, hyperthyroidism medicine lecture, hyperthyroidism pathology, thyroid scan, hyperthyroidism neetpg, hyperthyroidism usmle

Id: BCJfyMJWGb8

Length: 31min 10sec (1870 seconds)

Published: Sat Mar 02 2024