Is Hashimoto’s same as Hypothyroidism?
When one uses the term hypothyroidism one usually relates it with Hashimoto disease. But this is a wrong concept. Though Hashimoto has got all the signs and symptoms related to hypothyroidism, but it has got different aetiology. Hypothyroidism is a broader term which comprises everything, which is responsible for decrease hormone production. There are various etiologies, which are responsible for the disease. But Hashimoto is a type of hypothyroidism which is an immune response mounted by the body against its own cells. Thus when body cells attack its own thyroid follicles there is decrease in thyroid hormone and thus signs of hypothyroidism are seen.
What are The Causes of Hypothyroidism?
The causes can be divided into primary, transient and secondary.
So various causes are as follows-
- Autoimmune cause which includes Hashimoto’s thyroiditis.
- Drugs which include lithium and amiodarone prevent the conversion of T4 to T3.
- Antithyroid drugs in excess can even suppress thyroid production. Thus one should be careful while prescribing drugs for hyperthyroidism. Over enthusiastic intake can even cause harm in long run.
- Over expression of Type-3 deiodinase in infantile hemangioma.
- Iodine deficiency is major problem of hypothyroidism in endemic areas and goiter is prevalent in such areas.
- Hypothyroidism associated with other autoimmune diseases which include diabetes, vertigo.
- Infiltrative disorders such as sarcoidosis, scleroderma and hemochromatosis.
- After treatment with radioactive iodine.
- Withdrawal of thyroxine treatment.
- Apart from this pituitary surgery can even cause suppression of thyroid function.
- Hypothalamic disease which includes tumors or trauma to pituitary gland.
- Bexarotene treatment.
What are the Symptoms of Hypothyroidism?
- Tiredness, fatigue
- Dry skin
- Impaired learning and forgetfulness
- Weight gain
- Hoarse voice
What are the Signs of the Disease?
- Delayed tendon reflex relaxation
- Puffiness around the eyes.
- Dry and rough skin
- Absence of lateral eyebrow
- Diffuse alopecia
- Carpel tunnel syndrome
- Effusion in various cavities including middle ear which causes conductive deafness.
Evaluation of TSH should be done-
- If is it elevated then measure unbound T4.
- If it is normal then it is mild hypothyroidism
- If it is low then it is primary hypothyroidism. If autoantibodies are present then treat with T4.
- If autoantibodies are absent then rule out other causes.
If TSH comes out to be normal then suspect pituitary disease. If it is present then check unbound T4 if it is low then check for drug affecting the thyroid gland.
Treatment of Hypothyroidism
Daily replacement of thyroxine should be done. Usually 1.6 microgram/kg/body weight is given. Adult patients having heart disease may be given 50-100 microgram of levothyroxine daily. The treatment regimen can be changed daily based upon the TSH level. TSH levels should be monitored after 2 months of treatment as levothyroxine effects takes longer time to appear.
Once the normal TSH levels are attained one is advised for regular follow up for at least 2-3 years. A person who is taking more than 200 microgram of levothyroxine and still having signs and symptoms of hypothyroidism then surely he/she is not adhering to the medical treatment. This can be also because of fluctuation which occurs in TSH levels despite constant drug therapy. A person who shows high T4 level and high TSH level that means he/she is not taking the drugs regularly and drug is taken few days prior to measurement of TSH. In such conditions T4 get normalize while TSH remains high as TSH requires some time to get normalize. Thus this is a good way of diagnosing that who is taking medications. So treatment of thyroid is mandatory in all age groups but special care should be taken in case of pregnant women and neonates who are at high risk.
Thus neonatal screening is mandatory these days. So heel prick test is done to rule out hypothyroidism in new born. So hypothyroidism should be treated properly so as to prevent its complications. Few precautions include appropriate iodine intake in diet can even resolve problem in many areas.