Fatigue...Weight gain...Depression...Hair loss... 

They are common symptoms to an underlying health problem, one that leaves many women asking "Do I have an underactive thyroid?" The answer is -- it's quite possible. 

An underactive thyroid can cause many health problems. Hypothyroidism is more common than you might think -- up to 15 percent of women older than age 70 are affected, and doctors recommend that women older than 50 be screened annually.

Women are about 10 times more at risk than men to have the condition. All newborns are screened for congenital hypothyroidism. The condition can cause delayed mental development in newborns and a host of other health complications for older people. Read on to learn more about symptoms, treatments and factors that influence your risk. 

Signs of an underactive thyroid may include: 

• lower energy levels;
• weight gain;
• sensitivity to cold;
• constipation;
• muscle weakness and cramps;
• dry and scaly skin;
• puffy face;
• brittle nails;
• thinning hair;
• depression;
• loss of libido;
• irregular or heavy periods;
• memory problems (in the elderly);
• slower growth and development;
• early puberty;
• jaundice (in infants);
• frequent choking (in infants); and
• large and protruding tongue (in infants). 

An underactive thyroid does not produce enough thyroid hormone. Thyroid hormones travel through the bloodstream and affect nearly every part of the body, from the heart and brain to the muscles and skin. The thyroid uses fats and carbohydrates and helps regulate protein production, metabolism, body temperature and heart rate. An underactive thyroid causes body processes to slow down, leading to weakness, fatigue and complications that may mimic other health conditions. 

Those at Risk for Underactive Thyroid 

The Mayo Clinic mentions a number of risk factors for hypothyroidism. Women are more likely to have an underactive thyroid than men, especially older women. Women who have been pregnant or delivered in the past six months may be at a higher risk. Those with autoimmune diseases or close relatives who had autoimmune diseases may be at higher risk. Treatment with radioactive iodine, anti-thyroid medications or having the thyroid removed may put patients at greater risk. Radiation exposure to the upper chest or neck also puts people at greater risk. 

Causes of Underactive Thyroid 

There are many different causes of underactive thyroid. Iodine deficiency, which is a lack of iodine in one's diet, may cause hypothyroidism. Another cause is Hashimoto's disease, an autoimmune disorder that causes immune cells to attack and destroy cells at the thyroid gland. 

Pituitary gland dysfunction could cause hypothyroidism when the master gland does not make enough thyroid-stimulating hormone. This is a rare cause of underactive thyroid, however, and is often associated with a tumor on the pituitary gland. 

Simply getting the thyroid removed to treat hyperthyroidism (an overactive thyroid) can cause hypothyroidism. Radioactive iodine and anti-thyroid medications used to treat hyperthyroidism also could lead to hypothyroidism. 

What Happens If an Underactive Thyroid Goes Untreated 

Symptoms of an underactive thyroid often are mistaken for other conditions, so people may ignore the condition. But many problems can arise if the thyroid goes untreated. Some problems are not as serious as others, while some can be deadly. 

Patients may notice the following symptoms, which a doctor should examine:

• weight gain;
• dry skin and hair;
• hair loss;
• fatigue; and
• muscle aches. 

The Mayo Clinic lists these and other complications that may indicate an underactive thyroid: 

• high LDL cholesterol (the "bad" cholesterol);
• a goiter, or lump in the throat, which can be unsightly and affect swallowing and breathing;
• peripheral nerve damage;
• depression and other mental health problems;
• infertility stemming from problems with ovulation;
• birth defects if the mother has hypothyroidism; and
• more. 
  

Further, a study suggests that hospitalized patients with low thyroid levels could be at a greater risk of death. Scientists measured thyroid hormone levels in patients 65 and older upon admission to the Hospital General in Segovia, Spain in 2005. Researchers tracked hospital stay duration and survival rates among the 404 patients in the study as of January 1, 2012. They found an association between low thyroid hormone and mortality. 

If you have hypothyroidism – or suspect you might – speak with your doctor about these complications and what you can do to treat your condition or test to see if you have it. 

Treatment for Hypothyroidism 

Treatment may include synthetic thyroid hormone called levothyroxine to build up hormone levels. Taking this medication is usually a lifelong treatment with good results. The doctor will check thyroid-stimulating hormone levels after a few months of treatment to determine if the patient is taking the proper dosage. Just remember, finding the right dose may take time. So if the medication doesn't work right away, it may only be a matter of adjusting the dose. 

Be sure to discuss possible side effects of this or any other treatment with your doctor before taking the medicine. Side effects might include insomnia, tremors, headache, nausea, cramping, increased appetite, heat sensitivity and more. 

Some foods or minerals may affect the way the medicine works. For example, if you take antacids, your doctor may recommend you take them or other medication at least four hours before or after you take this medication. Other medications or substances that might interfere with levothyroxine may include soy products, iron supplements, cholestramine, sodium polystrene sulfonate and more. 

Hypothyroidism is a manageable condition – it's simply a matter of being diagnosed properly and monitoring the condition and your health. Most people who are diagnosed and treated for hypothyroidism lead healthy, normal lives.