Chronic hepatitis C infection is also associated with many autoimmune diseases
(where the body develops antibodies which attack parts of itself). For
example, about one-tenth of people with chronic hepatitis C infection
(more often in women and older people) have antibodies to the thyroid
gland, one-half of whom may develop hypothyroidism (an underactive
thyroid gland).
Additionally, interferon therapy causes hypothyroidism or hyperthyroidism (an
overactive thyroid gland) in about one-tenth of those treated.
People with hypothyroidism may suffer from fatigue, poor memory, weakness,
constipation, weight gain, muscle cramps, intolerance to cold, hoarse
voice, coarse skin, and brittle hair. People with hyperthyroidism may
suffer from anxiety, insomnia, weakness, diarrhea, weight loss,
intolerance to heat, velvet-like skin, and brittle nails. Hypothyroidism
can be treated with thyroid hormone pills.
Hyperthyroidism can be treated with pills that block thyroid hormone synthesis. If the thyroid gland dysfunction is from interferon treatment and is caught early, the thyroid gland will return to normal once interferon is stopped.
