Hypothyroidism is the disease state in humans and in animals caused by insufficient production of thyroid hormone by the thyroid gland.

Causes

• Iodine Deficiency
• Diseases such as Hashimoto thyroiditis
• Lack of thyroid gland
• Deficiency of hormones from the brain

Symptoms

• Early Symptoms
  • Poor muscle tone
  • Fatigue
  • Cold intolerance, increased sensitivity to cold
  • Depression
  • Muscle cramps and joint pain
  • Goiter
  • Thin, brittle fingernails
  • Thin, brittle hair
  • Paleness
  • Decreased sweating
  • Dry, itchy skin
  • Weight gain
  • Bradycardia (low heart rate – less than sixty beats per minute)
  • Constipation
• Late Symptoms
  • Slow speech and a hoarse breaking voice – deepening of the voice can also be noticed
  • Dry puffy skin, especially on the face
  • Thinning of the outer third of the eyebrows (sign of Hertoghe)
  • Abnormal menstrual cycles
  • Low basal body temperature

Treatment

• Hypothyroidism is treated with thyroid hormones (L-T₄) and (L-T3) available in the form of tablets.
• Thyroid hormone is taken daily, and doctors can monitor blood levels to help assure proper dosing.