High estrogen, and thyroxine cause it to increase.
Elevated SHBG may be encountered in hyperthyroidism and hepatic cirrhosis. High levels are also found in a variety of other conditions, such pregnancy.
Patients with anorexia nervosa have high SHBG levels. With successful treatment, levels start to fall as nutritional status improves. Normalization of SHBG precedes, and may be predictive of, future normalization of reproductive function.
High levels of SHBG can be related to:
Hepatitis
Hyperthyroidism
HIV
Anticonvulsants, or medicine used to treat seizures