If LH remains high through the menstrual cycle, it means no ovulation is occurring; this could either be due to the natural process of menopause or due to a dysfunction of ovaries in younger individuals. Polycystic ovary syndrome (PCOS) is another condition associated with high LH levels, and it affects around 1 in 10 women worldwide. Whatever the condition, elevated LH causes infertility.
Increased LH levels are due to a primary ovarian disorder, but in the case of decreased LH levels, the ovarian disorder is secondary to scarcity of LH. Eating disorders that lead to malnutrition, like anorexia or bulimia, are associated with a deficiency due to endocrine disruption. In the case of a pituitary disorder like hypopituitarism, the gland will fail to produce enough of multiple hormones including LH.
Just like in women, a surplus of LH is due to a primary gonadal disorder. A testicular dysfunction due to cancer treatment with either chemotherapy or radiotherapy causes an elevation of LH due to cellular damage. Chronic kidney disease and renal failure have been linked to high LH concentrations due to secretory dysregulation. Excessive alcohol consumption, either acute or chronic, has also been associated with hypogonadism and increased LH. Pituitary gland dysfunction affects men as much as women; the dip in LH due to hypopituitarism causes a decrease in testosterone affecting sexual drive and fertility.