Losing weight without trying may sound like a dream come true, but it could also indicate a serious health problem. Unexplained weight loss is when you lose more than 5 percent of your body weight in 6 to 12 months without a clear reason. It can affect anyone, but it’s more common in older adults and men.
Unexplained weight loss can have many causes, ranging from harmless to life-threatening. Some of the most common ones are:
- Muscle loss: This happens when you don’t use your muscles enough, such as if you have a desk job, a chronic illness, or an injury. Muscle loss can also be caused by aging, burns, stroke, arthritis, osteoporosis, multiple sclerosis, nerve damage, and other conditions. The main symptom is muscle weakness and one of your limbs may even look smaller than the other. To prevent or reverse muscle loss, you need to exercise regularly and eat enough protein and calories. You may also need supplements or medications to treat the underlying cause.
- Overactive thyroid: This occurs when your thyroid gland produces too much thyroid hormone. These hormones control your metabolism and how you use energy. If your thyroid is overactive, you’ll burn calories faster than usual even if you have a good appetite. This can result in unexplained weight loss. Other symptoms include fast, irregular heart rate, anxiety, fatigue, heat intolerance, sleep troubles, hand tremors, and light periods in women. Possible causes of overactive thyroid include Graves’ disease, thyroiditis, eating too much iodine, or taking too much thyroid medicine. Treatment options include anti-thyroid medications, radioactive iodine, beta-blockers, or surgery.
- Rheumatoid arthritis: This is an autoimmune disease that makes your immune system attack your joints, causing inflammation and pain. Chronic inflammation can speed up your metabolism and reduce your overall weight. Rheumatoid arthritis usually affects the same joints on both sides of your body. You may also feel stiff if you don’t move for an hour or more. The exact cause of rheumatoid arthritis is unknown, but it may be linked to age, genes, hormonal changes, smoking, secondhand smoking, and obesity. Treatment of rheumatoid arthritis typically involves medication such as disease-modifying antirheumatic drugs (DMARDs), corticosteroids, biologics, or Janus associated kinase inhibitors (JAK inhibitors).
- Diabetes: This is a condition that affects how your body uses glucose (sugar) for energy. There are two main types of diabetes: type 1 and type 2. Type 1 diabetes occurs when your immune system destroys the cells that make insulin in your pancreas. Insulin is a hormone that helps glucose enter your cells. Without insulin, glucose builds up in your blood and causes high blood sugar levels. This can make you lose weight because your body breaks down fat and muscle for energy instead of glucose. Type 2 diabetes occurs when your body becomes resistant to insulin or doesn’t make enough of it. This also leads to high blood sugar levels and weight loss because your cells don’t get enough glucose for energy. Other symptoms of diabetes include increased thirst and urination, hunger, blurred vision, fatigue, and slow-healing wounds. Possible causes of diabetes include genetics, autoimmune disorders, obesity, physical inactivity, and poor diet. Treatment of diabetes involves taking insulin injections or oral medications, monitoring blood sugar levels, eating a healthy diet, and exercising regularly.
- Cancer: This is a group of diseases that involve abnormal cell growth that can spread to other parts of the body. Cancer can cause unexplained weight loss due to loss of appetite, nausea, vomiting, and diarrhea from chemotherapy and emotional stress. It can also affect your metabolism and hormone levels, making you burn more calories than usual. Other symptoms of cancer depend on the type and location of the tumor, but they may include pain, lumps, bleeding, changes in bowel or bladder habits, coughing, difficulty swallowing, and skin changes. Possible causes of cancer include genetics, environmental factors, infections, and lifestyle habits such as smoking, drinking alcohol, and eating processed foods. Treatment of cancer depends on the type and stage of the disease, but it may include surgery, radiation therapy, chemotherapy, immunotherapy, targeted therapy, or hormone therapy.
If you notice unexplained weight loss along with any other symptoms mentioned above, you should see your doctor as soon as possible. They will perform a physical exam and order some tests to find out the cause of your weight loss and recommend the best treatment for you. Remember that not all weight loss is serious, but it’s better to be safe than sorry.