Early symptoms:

• Weakness
• Fatigue
• Cold intolerance
• Constipation
• Weight gain (unintentional) 
• Depression
• Joint or muscle pain
• Thin, brittle fingernails
• Thin and brittle hair
• Paleness

Late symptoms:

• Slow speech
• Dry flaky skin
• Thickening of the skin
• Puffy face, hands and feet
• Decreased taste and smell
• Thinning of eyebrows
• Hoarseness
• Abnormal menstrual periods

Additional symptoms that may be associated with this disease:

• Overall swelling
• Muscle spasms (cramps)
• Muscle pain
• Muscle atrophy
• Uncoordinated movement
• Absent menstruation
• Joint stiffness
• Dry hair
• Hair loss
• Drowsiness
• Appetite loss
• Ankle, feet, and leg swelling
• Short stature
• Separated sutures 
• Delayed formation or absence of teeth

A physical examination reveals delayed relaxation of muscles during tests of reflexes. Other findings may include pale, yellow skin, thin and brittle hair, coarse facial features, brittle nails, firm swelling of the arms and legs, and mental slowing. Vital signs may show slow heart rate, low blood pressure, and low temperature.

A chest x-ray may show an enlarged heart.

Laboratory tests to determine thyroid function include:

• T4 test (low)
• Serum TSH (high in primary hypothyroidism, low or low-normal in secondary hypothyroidism)

Additional laboratory abnormalities may include:

• Increased cholesterol levels 
• Increased liver enzymes
• Increased serum prolactin
• Low serum sodium
• A complete blood count (CBC) that shows anemia