Hypothyroidism is Thyroid hormone deficiency. It is diagnosed by clinical features such as a typical facial appearance, hoarse slow speech, and dry skin and by low levels of thyroid hormones. Management includes treatment of the cause and administration of thyroxine.
Hypothyroidism occurs at any age but is particularly common among the elderly, where it may present subtly and be difficult to recognize. Hypothyroidism may be:
· Primary: caused by disease in the thyroid
· Secondary: caused by the disease in the hypothalamus or pituitary.
Subclinical hypothyroidism is elevated serum TSH in patients with absent or minimal symptoms of hypothyroidism and normal serums of free T4.
Subclinical thyroid dysfunction is relatively common; it occurs in more than 15% of an elderly woman and 10% of elderly man, particularly in those with underlying Hashimoto thyroiditis.
In patients with serum TSH> 10mU/L, there is a high likelihood of progression to overt hypothyroidism with low serum levels of free T4 in the next 10yr. These patients are also more likely to have hypercholesterolemia and atherosclerosis. They should be treated with L-thyroxine, even if they are asymptomatic.
For patients with TSH level between 4.5 and 10 mU/L, a trial of L-thyroxine is reasonable if symptoms of hypothyroidism (eg fatigue, depression) are present.
L-thyroxine therapy is also indicated in pregnant woman and in a woman who plans to become pregnant to avoid deleterious effects of hypothyroidism on the pregnancy and fetal development. Patients should have an annual measurement of serum TSH and free T4 to assess the progress of the condition if untreated or to adjust the L-thyroxine dosage.
Signs and Symptoms
Symptoms & Signs of primary hypothyroidism are often subtle and insidious. Various organ system may be affected.
· Metabolic manifestations: Cold intolerance, modest weight gain (due to fluid retention and decreased metabolism), hypothermia
· Neurologic manifestations: Forgetfulness, paresthesia’s of the hands and feet (often due to carpal tunnel syndrome caused by due to a proteinaceous ground substance in the ligaments around the wrist and ankle); slowing of the relaxation phase of deep tendon reflexes.
· Psychiatric manifestations: Personality changes, depression, dull the facial expression, dementia or frank psychosis (myxedema madness).
· Dermatologic manifestations: Facial puffiness; myxedema; sparse, coarse and dry hair; coarse, dry, scaly, and thick skin; carotenemia, particularly notable on the palms and soles (caused by deposition of carotene in the lipid-rich epidermal layers); macroglossia due to deposition of a proteinaceous ground substance in the tongue.
· Ocular manifestations: Periorbital swelling due to infiltration with the mucopolysaccharides hyaluronic acid and chondroitin sulfate, droopy eyelids because of the decreased adrenergic drive.
· Gastrointestinal infestations: Constipation
· Gynecologic manifestation: Menorrhagia or secondary amenorrhea.
· Cardiovascular manifestations: Slow heart rate (a decrease in both thyroid hormone and adrenergic stimulation causes bradycardia), enlarged heart on examination and imaging (partly because of dilation but chiefly because of pericardial effusion develops slowly and only rarely cause hemodynamic distress).
· Other manifestations: Pleural or abdominal effusions (pleural effusions develop slowly and only rarely cause respiratory or hemodynamic distress), hoarse voice and slow speech.
Symptoms can differ significantly in elderly patients.
Although secondary hypothyroidism is uncommon, it causes often affect another endocrine organ controlled by the hypothalamic-pituitary axis. In a woman with hypothyroidism, indications of secondary hypothyroidism are a history of amenorrhea rather than menorrhagia and some suggestive differences on physical examination.
Secondary hypothyroidism is characterized by skin and hair that are dry but not very coarse, skin depigmentation, only minimal macroglossia, atrophic breasts, and low BP. Also, the heart is small and serious pericardial effusions do not occur. Hypoglycemia is common because of concomitant adrenal insufficiency or growth hormone deficiency.
Myxedema coma is a life-threatening complication of hypothyroidism, usually occurring in patients with a long history of hypothyroidism. Its characteristics include coma with extreme hypothermia (temperature 24o to 34.2o C), areflexia, seizures, and respiratory depression with carbon dioxide retention. Severe hypothermia may be missed unless low-reading thermometers are used.
Rapid diagnosis based on clinical judgment, history, and physical examination is imperative because death is likely without rapid treatment. Precipitating factors include illness, infection, trauma, drugs that suppress the CNS, and exposure to cold.
· Free Thyroxine(T4)
Anaemia is often present, usually normocytic-normochromic and of unknown aetiology, but it may be hypochromic because of menorrhagia and sometimes macrocytic because of associated pernicious anaemia or decreased absorption of folate.
Anaemia is rarely severe (Hb usually> 9g/dL). As the hypometabolic state is corrected, anaemia subsides, sometimes requiring 6 to 9 mo.
Serum cholesterol is usually high in primary hypothyroidism but less so in secondary hypothyroidism.
Screening for hypothyroidism is warranted in select populations (eg, the elderly), in which it is relatively more prevalent, especially because of its manifestations can be subtle. Screening is done by measuring TSH levels.
· L-Thyroxine, adjusted until TSH level is in a mid normal range
Myxedema coma is treated as follows:
· T4 given IV
· Supportive care as needed
· Conversion to oral T4 when the patient is stable
Hypothyroidism is particularly common among the elderly. It occurs in close to 10% of women and 6% of men> 65. Although typically easy to diagnose in younger adults, hypothyroidism may be subtle and manifest atypically in the elderly.
Elderly patients have significantly fewer symptoms than do younger adults, and complaints are often subtle and vague. Many elderly patients with hypothyroidism present with nonspecific geriatric syndromes- confusion, anorexia, weight loss, falling, incontinence, and decreased motility. Musculoskeletal symptoms (especially arthralgia) occur often, but arthritis is rare. Muscular aches and weakness, often mimicking polymyalgia rheumatic or polymyositis, and an elevated CK level may occur. In the elderly, hypothyroidism may mimic dementia or parkinsonism.
In the elderly, L-thyroxine therapy is begun with low doses, usually, 25mcg once/day. Maintenance doses may also need to be lower in elderly patients.
Hypothyroidism occurs when levels of the two thyroid hormones, triiodothyronine (T3) and thyroxine (T4), is too low. Although changing your diet alone isn’t enough to restore normal thyroid hormone levels, avoiding some foods and eating more of others can improve your body’s absorption of these hormones.
Foods to avoid
Many common foods and supplements contain compounds that interfere with thyroid function. In general, its best to avoid the following:
Studies suggest that phytoestrogens in soybeans and soy-rich foods may inhibit the activity of an enzyme that makes thyroid hormones. One study found that women who consumed soy supplements were three times more likely to develop hypothyroidism.
Iodine rich foods
Some forms of hypothyroidism are caused by a lack of sufficient iodine. In such cases, using iodized salt or iodine enriched foods can be beneficial. But eating too much iodine can have the opposite effect and suppress thyroid gland activity. Check with your doctor before taking supplements.
Iron and calcium supplements
Taking iron or calcium supplements can also change the effectiveness of many thyroids medications.
High fibre foods
Although a high-fibre diet is usually recommended, too much fibre eaten right after taking thyroid medicines may interfere with their absorption. Wait two hours before you eat a high fibre meal (having more than 15gms of fibre).
Cruciferous vegetables that are rich in fibre, like broccoli, cabbage, spinach, kale, and Brussels sprouts may inhibit thyroid medication absorption. Reducing the amounts of such products in the morning right after taking your medication may help.
Caffeine, tobacco and alcohol can also influence the effectiveness of thyroid medicine. Ask your doctor for tips on how to regulate or reduce your consumption.
Foods to eat
Nutrient-rich foods that improve your health may also benefit your thyroid gland. Certain compounds and supplements may help as well.
Antioxidant-rich fruits and vegetables
Blueberries, tomatoes, bell peppers, and other food rich in antioxidants can improve overall health and benefit the thyroid gland. Eating foods high in Vitamin B like the whole grains may also help.
Tiny amounts of selenium are needed for the enzymes that make thyroid hormones to work properly. Eating selenium-rich foods, such as sunflower seeds or Brazil nuts can be beneficial.
This amino acid is used by the thyroid gland to produce T3 and T4. Good sources of tyrosine are meats, dairy, and legumes. Taking a supplement may help, but ask your doctor beforehand.
Diet plans and herbal supplements
Hypothyroidism doesn’t have to prevent or limit you from following a healthy lifestyle. People with hypothyroidism can choose to be vegetarian, eat protein-rich foods, and avoid ingredients that may cause an allergy.
You may also decide to use alternative medicines for hypothyroidism. Some plant extracts like ashwagandha (Withania somnifera), coleus (Coleus forskohlii), Gotu kola (Centella Asiatica), guggul (Commiphora Mukul), may ease symptoms of hypothyroidism.
Evidence to support these claims is limited, however. Always speak with your doctor before making any big changes to your eating habits or before taking any supplements. Having your doctor routinely check your thyroid levels can also provide insight into how your lifestyle changes are affecting your thyroid and your overall metabolism.
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