What are the symptoms of hypothyroidism?

Comprehensive List of Hypothyroid Symptoms

Hypothyroidism presents with a wide range of symptoms affecting multiple body systems due to decreased metabolic rate and reduced thyroid hormone activity. 1

Common Symptoms

Metabolic and General Symptoms

• Fatigue and lethargy 1, 2
• Weight gain and difficulty losing weight 1, 2, 3
• Cold intolerance (increased sensitivity to cold) 1, 3, 4
• Low metabolic rate 1, 3
• Decreased heat production by the body 3

Neurological and Cognitive Symptoms

• Memory loss 2, 5
• Difficulty concentrating 2, 5
• Intellectual slowness 1
• Depression 1
• Somnolence (excessive sleepiness) 1

Dermatological Symptoms

• Dry skin (xeroderma) 1, 3, 4
• Hair loss 1
• Myxedema (non-pitting edema/swelling) 1

Gastrointestinal Symptoms

• Constipation 1, 3
• Irregular bowel movements 3, 4

Cardiovascular Symptoms

• Bradycardia (slow heart rate) 1
• Mild hypertension (often diastolic) 1
• Narrowed pulse pressure 1
• Pericardial effusions (in severe cases) 1

Musculoskeletal Symptoms

• Muscle cramps 1
• Muscle weakness 1

Reproductive and Endocrine Symptoms

• Menstrual irregularities 2
• Oligomenorrhea (infrequent menstruation) 2
• Menorrhagia (heavy menstrual bleeding) 2
• Disrupted ovulation 2
• Infertility 2, 6
• Increased risk of miscarriage 2

Voice and Speech Changes

• Voice changes (deeper, hoarse voice) 1, 4

Advanced or Severe Symptoms

Myxedema Coma (Life-threatening complication)

• Hypothermia 2
• Hypotension 2
• Altered mental status 2
• Requires intensive care treatment 2
• High mortality rate (up to 30%) 2

Metabolic Complications

• Insulin resistance 2
• Hyperglycemia in diabetic patients 2
• Increased risk for cardiovascular events 2
• Heart failure 1, 2

Special Considerations

Laboratory Findings

• Elevated thyroid-stimulating hormone (TSH) 1, 2
• Low free thyroxine (T4) 1, 2
• Low triiodothyronine (T3) in some cases 3

Risk Factors

• Female sex (more common in women) 2, 3
• Older age 2, 3
• Family history of thyroid disease 2
• History of autoimmune disorders 2
• Previous radiation therapy to the neck 2, 3
• Thyroid surgery 2, 3
• Certain medications (e.g., immune checkpoint inhibitors, amiodarone) 2

Diagnostic Pitfalls

• Symptoms can be nonspecific and easily overlooked 3, 4
• Symptoms may overlap with other conditions 3
• Early disease may present with minimal symptoms 4
• Acute illness, diet, and certain drugs may alter thyroid function test values 6

Early recognition and appropriate treatment with levothyroxine can effectively manage these symptoms and prevent progression to more severe complications 2, 4.