Symptoms of Hypothyroidism
Hypothyroidism presents with a wide range of symptoms including fatigue, muscle cramps, constipation, cold intolerance, weight gain, hair loss, dry skin, voice changes, intellectual slowness, and insomnia. 1 These symptoms result from decreased metabolic activity throughout the body due to thyroid hormone deficiency.
Common Symptoms
The clinical presentation of hypothyroidism can vary significantly in severity and may include:
Early/Common Symptoms
- Fatigue and lethargy
- Cold intolerance
- Weight gain
- Constipation
- Dry skin (xeroderma)
- Hair loss
- Muscle cramps
- Depression
- Voice changes (hoarseness)
Advanced Symptoms
- Intellectual slowness
- Insomnia
- Edema
- Bradycardia
- Myxedema (in severe cases)
- Myxedema coma (life-threatening condition) 1
Symptom Variations by Population
Women
- Irregular menstrual cycles
- Fertility issues
- Increased risk of miscarriage
- Increased risk of preeclampsia during pregnancy 1, 2
Elderly
- Symptoms may be more subtle or attributed to aging
- May present primarily with cognitive changes
- Higher prevalence in this population 3
Laboratory Findings
While not symptoms per se, laboratory abnormalities are essential for diagnosis:
- Elevated TSH (thyroid-stimulating hormone)
- Low free T4 (thyroxine) levels 3
Subclinical Hypothyroidism
This condition is characterized by:
- Elevated TSH with normal free T4
- May be asymptomatic or have minimal symptoms
- Affects 6-20% of patients in clinical trials 1, 3
Severe Manifestations
If left untreated, hypothyroidism can progress to:
- Myxedema coma - a medical emergency characterized by profound hypothermia, bradycardia, hypotension, hypoventilation, and altered mental status
- Congenital cretinism in infants born to mothers with untreated hypothyroidism (growth failure, mental retardation, neuropsychologic defects) 1, 4
Diagnostic Pitfalls
- Symptoms are often nonspecific and can overlap with many other conditions
- Early symptoms may be subtle and easily missed
- Laboratory testing (TSH and free T4) is essential for diagnosis, as symptoms alone are insufficient 3, 5
- Symptoms may persist in some patients despite normalization of thyroid function tests with treatment 5
Recognizing the constellation of symptoms is crucial for early detection and treatment of hypothyroidism, which can significantly improve quality of life and prevent progression to more severe manifestations.