HYPOTHYROIDISM

Clinical features

Haematological

• Tiredness

• Somnolence

• Anaemia

• Weight gain

• Iron deficiency- Pale conjunctiva

– Gold intolerance

• Hoarseness

• Goitre

Dermatological

• Dry, flaky skin

– hair, alopecia

Cardio/respiratory

– Hypertension

• Purplish lips

– Angina

-Cardiac failure

• Vitiligo

• Myxoedema

Neuromuscular

Aches and pains

Muscle stiffness

Decreased tendon reflexes

Carpal tunnel syndrome

Cerebellar ataxia

Myotonia

Reproductive

• Menorrhagia

• Delayed relaxation

• Infertility

• Galactorrhoea

• Impotence

Gastrointestinal

• Constipation

• Ileus

-Ascites

Psychiatric

Depression

Psychosis

Endocrine

Goiter

EXAMINATION OF HYPOTHYROID PATIENT

Hands

• Peripheral cyanosis

• Swelling

• Dry cold skin

• Anemia

Arms

Pulse

Bradycardia

Small volume pulse

• Test for carpal tunnel syndrome by tapping the flexor retinaculum medial to the base of the thenar eminent with the wrist extended.

• Biceps reflex: delayed.

• Test for proximal myopathy (Rare)

Face

Alopecia

Dry thin hair

Mental slowness

Depression

Look for general swelling and periorbital edema

Loss of outer halves of eyebrows

Vitiligo

The tongue may be swollen

Check hoarseness of voice and slowness of speech

Test for deafness which may be bilateral and due to nerve involvement.

Legs

• Slow relaxation of ankle jerk

• Peripheral neuropathy

• Edema

Chest

• Pleural or pericardial effusion

• Rough sandpaper-like skin over the chest

INVESTIGATIONS

Thyroid function tests

• Serum T4 – low

• Serum TSH – high in primary and normal or low in secondary hypothyroidism due to pituitary insufficiency.

• There are increased circulating levels of antithyroid peroxidase or antithyroglobulin antibodies in patients with Hashimoto’s thyroiditis.

Other laboratory findings

• Serum lactate dehydrogenase (LDH) & creatinine kinase are raised.

• Serum cholesterol and triglyceride are raised.

• Serum sodium – may be decreased.

• Anemia with normal or increased MCV.

ECG shows sinus bradycardia with low voltage complexes.

Complications

• Coronary artery disease and cardiac failure due to hyperlipidemia.

• Increased susceptibility to infection.

• Megacolon.

• Myxedema madness: psychosis with paranoid delusions.

• Infertility (rare).

Pregnancy in hypothyroidism often results in miscarriage. Babies born to hypothyroid mothers have an IQ level less than normal.

Management

Thyroxine replacement

Repeat HSH in 6 weeks

The patient feels better within 2-3 weeks. Reduction in weight and periorbital puffiness occurs quickly, but the

restoration of skin texture takes 3-6 months.

Hypothyroidism and pregnancy

Pregnant women require 50 mcg more thyroxine than non-pregnant women. This is because during pregnancy there is increased serum thyroxine-binding globulin, therefore serum-free thyroid hormone concentration decreases.