Difference Between Hypothyroidism and Hyperthyroidism

The thyroid gland is an important endocrine organ in the human body and it secretes thyroxin (T4) and tri-iodothyronine (T3), which in turn helps to maintain the metabolic functions of the human body, along with proper development of the human body at early stages and adequate neural development in the cortex. As it affects the overall metabolic functions of the human body, it affects all the aspects of system functions, thus, an excess or a deficit will affect the person in extremes of both directions to the normal function. The discussion will follow into the causes of these conditions, the symptoms and signs, and the management aspect.


Hypothyroidism is the deficit of thyroidal hormones causing a reduction in the expected actions. This can be due to a congenital cause, or iatrogenic, or caused by radiation, etc. This type of a patient will complain of cold intolerance, constipation, lethargy, weight gain, dry skin, heavy menstrual bleeds, and depression. The signs of hypothyroidism will include, dry skin, greater BMI, bradycardia, slow relaxing deep tendon reflexes, etc. The investigations will be done through a T4 and TSH levels, and this can assess if it is overt or subclinical hypothyroidism. The management will be through, correction of causative factor and supplementation of thyroidal hormones with levothyroxine, may be for the rest of the life.


Hyperthyroidism is the excess of thyroidal hormones causing acceleration in the expected actions. It may be caused by excess ingestion of iodine or thyroxin, a non cancerous growth, Grave’s disease, etc. This patient will complain of heat intolerance, loss of weight, loss of libido, agitation, tremor, irregular menstrual bleeding, excessive sweating, psychosis, etc. The signs will consist of, hyperhidrosis, fine tremor, hair loss, visible goiter, tachycardia, fast relaxing deep tendon reflexes, blood shot eyes, protruding eyes, nail deformities, etc. Here again the investigations consist of T4 and TSH levels, and also the specific investigations to elucidate the cause of the hyperthyroidism. The management will be dependent on the cause. Reducing the thyroidal levels by anti thyroid drugs is important, and then the specific interventions like surgery or radio iodine treatment can be chosen.

What is the difference between Hypothyroidism and Hyperthyroidism?

Both these conditions are associated with ill health and dysfunction of the normal life style of the person. Both conditions may be associated with goiters, and associated with muscle pain and fatigue. There are also menstrual irregularities, and loss of libido. Both conditions can give rise to pulmonary oedema, and heart disease. Other conditions are associated with psychiatric illnesses, which cause great distress to the individual. The specific signs and symptoms of these conditions lie at the extremes of the normal spectrum, thus when hypothyroidism cause cold intolerance, weight gain, dry skin, hyperthyroidism causes heat intolerance, weight loss and excess sweat. The investigative techniques are the same, but the management differs. Hyperthyroidism is usually managed with anti thyroid drugs, and surgery/ radio iodine without the need for long term drug management, lest there is an iatrogenic complication. Hypothyroidism on the other hand requires long term, maybe throughout life management with levothyroxine.

In summary these two conditions lie at the two extremes of normalcy in relation to thyroid levels, and cause considerable morbidity and mortality, unless managed properly.