A miscarriage, also known medically as a spontaneous abortion, is the natural loss of a fetus before the 20th week of pregnancy. Miscarriages occur for a range of reasons, including illness, infection, and hormonal or genetic abnormalities.

Progesterone is a steroid hormone made primarily in the ovaries but also by the placenta during pregnancy. Progesterone acts with other female hormones, such as estrogen, to maintain female reproductive health and female sex characteristics.

The adrenals are two small glands that sit on top of each kidney. They are responsible for managing blood sugar levels, regulating the balance of salt and water, and controlling sexual maturity. The adrenal glands also come to the rescue when a person is under stress.

Follicle-stimulating hormone, or FSH, helps regulate the reproductive processes in both men and women. It affects the growth process, puberty maturation and the development of the body. FSH levels are used to help diagnose a number of factors including fertility.

What you eat may contribute to the health of your thyroid, a gland located in your neck that produces hormones responsible for energy and metabolism.

Abnormally high thyroid hormone levels, or hyperthyroidism, can cause increased heart rate, anxiety and weight loss. When thyroid hormone levels drop too low the result is fatigue, weight gain and slowed heart rate, a condition known as hypothyroidism.

Hyperthyroidism is a condition in which the thyroid gland produces too much of the hormone thyroxine. Merck Manuals, an online medical library, reports that hyperthyroidism most commonly affects women after childbirth or menopause, but hyperthyroidism can affect men as well.

Progesterone is a hormone that women naturally produce after ovulation. It is sometimes called the "warm" hormone, because it causes a rise in basal body temperature (i.e., temperature when the body is completely at rest).

Cortisol is a hormone secreted by your adrenal glands that plays an important role in managing your body's response to stress. Cortisol mobilizes your body's energy reserves by increasing glucose levels in the blood, activating the conversion of proteins to carbohydrates and suppressing inflammation.

Your height is based in large part on genetics -- tall parents tend to have tall children. However, environmental factors, such as diet, have an influence, too. The long bones in your legs determine your height.

Estrogen is the primary hormone produced in the ovaries. The ovaries begin their production of estrogen in response to chemical stimulation from the area of the brain known as the pituitary gland.

Hormones are molecules that your body uses for communication, often between organs in different organ systems or over long distances in the body. There are two major types of hormones: steroid hormones and protein, or peptide, hormones.