Understanding Hypothyroidism

The thyroid gland in our necks is responsible for secreting the thyroid hormone which regulates a number of processes in the body. For any number of reasons that gland may be overactive or underactive and cause a disruption in that body processes that the hormone regulates. These conditions are known as hyperthyroidism when there is too much of the thyroid hormone and hypothyroidism when there is too little. Hypothyroidism is the more common one and could be a primary condition of the thyroid gland or it could be due to problem with the control mechanisms of the thyroid gland. The primary one is a more common cause of hypothyroidism and may be due to an autoimmune process affecting the gland. If this is severe in adults, it can cause and get called myxoedema and in children it causes what used to be called cretinism. The secondary cause is if there is a problem in the pituitary gland which controls the thyroid gland. It can also occur if the thyroid gland needs to be removed surgically or has radiation therapy for a cancer.

There is a condition which is called subclinical hypothyroidism that is alleged to start producing symptoms as the levels of the hormone reduces, but there is some controversy around if this is really a problem or not. The main clinical symptoms of a hypothyroidism is tiredness and fatigue with a duller facial expression (they often look unhappy) with some puffiness of the face. They appear somewhat pale and develop an intolerance to cold with Raynaud’s phenomenon being common. The skin becomes dry, cold and pale. In the later stages if treatment is not started there may be some personality changes. The ankle reflexes become delayed with a slow relaxation of the reflexes (called Woltman’s sign). An anaemia may develop. The skin becomes thicker due to increases dermal mucopolysaccharide accumulating (called myxoedema). There might be pain in the joints, most often the knee and pain in the hips is common. Some will develop a carpel tunnel syndrome in the wrist. The muscles can develop a persistent ache which may confuse the condition with fibromyalgia. A number of these symptoms do also develop in a somewhat normal way as we get older, which can also further confuse the diagnosis.

The diagnosis of hypothyroidism initially can be quite confusing as all of the symptoms could have other causes so all of that needs to be taken into account. It can be quite common not to make the diagnosis in the early stages and it is not made until more symptoms develop. The diagnosis is made based on the collection of the clinical features and laboratory testing of the blood levels of the thyroid hormone and other markers. Treatment is reasonably straight forward and is based on simply replacing the thyroid hormone, thyroxine, orally. There may be a little bit of trial and error to get the dose right based on blood testing and the response of the symptoms to the medication. A lot of the hypothyroidism symptoms are reversed once therapy is started.

Craig Payne is a University lecturer, runner, cynic, researcher, skeptic, forum admin, woo basher, clinician, rabble-rouser, blogger and a dad.