Millions of people, most of them women, suffer from thyroid disease. When your body produces too little thyroid hormone, the hormone responsible for metabolism, heart rate, and mood, you are said to have hypothyroidism, or an underactive thyroid. If your body makes too much of the hormone, you're said to have hyperthyroidism, or an overactive thyroid. Thyroid hormone is responsible for everything from your basal metabolic rate—the rate at which your body uses oxygen and energy to function—to the growth of your hair, skin, and nails. But when you don't have the right amount, you may notice changes in bodily functions.
The symptoms: Hypothyroidism (too little hormone) may cause a host of symptoms, including unexplained weight gain, fatigue, constipation, depression, and difficulty concentrating. Hair, nails, and skin may become more brittle and break more easily. It's more common in women, especially over the age of 50, says Theodore C. Friedman, MD, MPH, chief of the division of endocrinology, metabolism, and molecular medicine at Charles Drew University in Los Angeles and coauthor of The Everything Guide to Thyroid Disease (Adams Media, 2007). It affects about 5 percent of the US population but is nearly 10 times more frequent in women.
Hyperthyroidism (too much hormone) may cause inexplicable weight loss, heart palpitations, nervousness, irritability, diarrhea, moist skin, muscle weakness, and a startled appearance of the eyes. You may also experience hair loss as metabolism speeds up. Hyperthyroidism is much less common than hypothyroidism and affects about 1 percent of the US population.
The tests: A blood test measures thyroid-stimulating hormone, which is produced by the pituitary gland in an attempt to coax the thyroid to make thyroid hormone. Excess TSH usually indicates hypothyroidism, while abnormally low levels suggest hyperthyroidism.
What you can do: Your doctor may prescribe a thyroid hormone medication to restore levels to normal. Regular TSH tests might be done to ensure an adequate dosage.
Lupus is a chronic autoimmune disease in which the body's own immune system attacks healthy tissues. The condition affects about 1.5 million people and tends to strike women during their childbearing years.
The symptoms: Lupus often causes extreme fatigue, headaches, oral ulcers, and painful, swollen joints. Many people develop a butterfly-shaped rash across the bridge of the nose and become more sensitive to the sun. Other symptoms include fever; swelling in the feet and hands and around the eyes; chest pain; and anemia. Many people also experience hair loss, which may be mild and occur while shampooing or brushing your hair—or it may be more severe, coming out in patches and accompanied by a rash on the scalp, says Arthur Weinstein, MD, director of the division of rheumatology at the Washington Hospital Center. Because these symptoms occur in many other conditions, lupus is often called the great imitator.
The tests: A rheumatologist will examine joints and other tissues for signs of inflammation, such as heat, pain, swelling, and redness. A blood test to measure levels of anti-nuclear antibodies (ANA) may also indicate lupus. Rheumatologists will also determine if patients have four of 11 diagnostic criteria set by the American College of Rheumatology, though fewer criteria along with a skin biopsy may sometimes indicate lupus, Dr. Weinstein says.