What are the clinical features of hypothyroidism in females?

Clinical Features of Hypothyroidism in Females

Hypothyroidism in females presents with a constellation of metabolic, cardiovascular, reproductive, and systemic symptoms that reflect the widespread effects of thyroid hormone deficiency on multiple organ systems.

Metabolic and Constitutional Symptoms

The most prevalent manifestations of hypothyroidism in women stem from decreased metabolic rate:

• Fatigue and lethargy are the most common symptoms, affecting 68-83% of patients with hypothyroidism, representing the hallmark feature of metabolic slowing 1, 2
• Weight gain occurs in 24-59% of patients despite no increase in caloric intake, resulting from decreased fat-burning rate and reduced metabolic activity 1, 3, 2
• Cold intolerance develops due to decreased heat production by the body, a direct consequence of reduced metabolic rate 3, 4, 5
• Constipation results from slowed gastrointestinal motility secondary to decreased metabolic function 2, 4, 5

Cognitive and Neuropsychiatric Manifestations

Thyroid hormone deficiency significantly impacts mental function in women:

• Cognitive impairment affects 45-48% of patients, manifesting as memory loss, difficulty concentrating, and intellectual slowness 1, 2
• Depression is a common neuropsychiatric symptom that may be the presenting complaint in some women 2
• Somnolence (excessive sleepiness) reflects the overall metabolic slowing 2

Dermatologic and Physical Examination Findings

Women with hypothyroidism exhibit characteristic physical signs:

• Dry skin (xeroderma) and coarse skin texture are common dermatologic manifestations 3, 4, 2
• Hair loss occurs as a result of decreased metabolic activity affecting hair follicles 2, 1
• Myxedema (non-pitting edema/swelling) and periorbital puffiness represent accumulation of glycosaminoglycans in tissues 2
• Hoarseness and voice changes develop from laryngeal edema 4, 2
• Delayed ankle reflex is a specific neurologic finding that helps distinguish hypothyroidism from other conditions 2

Cardiovascular Manifestations

Hypothyroidism causes specific hemodynamic changes in women:

• Bradycardia (slow heart rate) results from decreased metabolic demands 2
• Mild diastolic hypertension with narrowed pulse pressure occurs due to increased systemic vascular resistance (up to 50% increase) 2
• Pericardial effusions can develop in severe cases 2
• Heart failure may occur as a complication, particularly in older women with underlying cardiac disease 2, 1

Musculoskeletal Symptoms

Thyroid hormone deficiency affects muscle function:

• Muscle weakness, particularly proximal muscle weakness, is common 2
• Muscle cramps occur frequently 2
• Slow movement reflects overall metabolic slowing 2

Reproductive and Gynecologic Manifestations

Hypothyroidism has profound effects on female reproductive health:

• Menstrual irregularities affect approximately 23% of women with hypothyroidism, including oligomenorrhea (infrequent periods) and menorrhagia (heavy menstrual bleeding) 1
• Disrupted ovulation and infertility result from thyroid hormone's critical role in reproductive function 1, 3
• Increased risk of miscarriage occurs in women with untreated hypothyroidism 1, 3
• Insulin resistance and hyperglycemia can develop in women with diabetes, complicating metabolic management 1

Laboratory Findings

The diagnosis is confirmed by biochemical testing:

• Elevated thyroid-stimulating hormone (TSH) is the primary laboratory finding 2, 1
• Low free thyroxine (T4) confirms overt primary hypothyroidism 2, 1

Severe Complications

If left untreated, hypothyroidism can progress to life-threatening conditions:

• Myxedema coma represents severe decompensation with hypothermia, hypotension, and altered mental status, carrying a mortality rate up to 30% 1, 3
• Mental retardation and delayed milestones can occur in infants born to mothers with untreated hypothyroidism 3

Important Clinical Considerations

The diagnosis of hypothyroidism in women can be perplexing because of its insidious onset and wide array of nonspecific manifestations 6. Symptoms may be attributed to emotional problems or other health conditions initially, and patients may not seek medical care because they are unaware they are ill 6. The signs and symptoms suggesting thyroid dysfunction are nonspecific and nondiagnostic, especially early in disease presentation 4.

Hypothyroidism is more common in women and older adults, with prevalence ranging from 0.3% to 12% worldwide depending on iodine intake 1. The disease affects every major organ system and metabolic process 6.

Clinical manifestations range from minimal to life-threatening, and presentation can differ with age, sex, and other factors 5. With appropriate levothyroxine replacement therapy, symptoms can be effectively managed and most women with hypothyroidism can lead normal, healthy lives 3.