Weight loss can be both intentional and unintentional. You may want to lose weight as part of getting in shape or improving your health, but you can also lose weight as the result of a health condition. 

Losing weight without trying can be dangerous, and is considered a health problem when you lose more than five percent of your body weight with a 6 to 12 month period. Weight loss in this manner could be a sign of a serious illness or a health condition that needs immediate medical attention.

Causes of Unintentional Weight Loss 

Losing weight can be beneficial when it is controlled and monitored. When you rapidly lose weight without trying, your health can suffer. 

If unintentional weight loss is the result of stress or a traumatic event, it will only be temporary, but if the cause is an underlying condition, you need to get treatment. By treating the condition causing your weight loss, you can restore health by regaining control over your weight loss. 

Common health conditions known to be associated with unintentional weight loss can include:


Cancer is the abnormal growth and spread of cells in the body. There are a number of factors within cancer that cause weight loss. 

Weight loss of 10 pounds or more rapidly is often one of the first signs of cancer, and this is largely due to the chronic inflammation in the body. Tumors also require a great deal of energy to grow and spread, and they get this from your body’s energy sources. Hormones also get disrupted, which causes loss of appetite and muscle wasting. 

Radiation treatment and chemotherapy are the best options for treating cancer, but these too can cause nausea and loss of appetite, which leads to further weight loss until the cancer is gone. 

Chronic Obstructive Pulmonary Disease (COPD)

Chronic Obstructive Pulmonary Disease or COPD consists of a group of progressive lung diseases, such as emphysema and chronic bronchitis. While emphysema damages your lung’s air sacs, bronchitis causes inflamed airways. 

All COPD conditions cause extensive damage to the lungs, which causes chest pain and chronic coughing. In the later stages of COPD, you can develop weight loss because labored breathing uses more energy. Both cause serious breathing issues, along with chest pain and coughing. Medications can help prevent these conditions from progressing, but avoiding smoking helps too. 


Depression is a mental health concern, but it can affect your behavior. Depression leads to fatigue and a lack of motivation, which reduces your desire for activities and even food. If eating habits change too much, you can lose weight. Some people may also lose weight as a side effect on antidepressant medications. 


Endocarditis is an inflammation of the lining of your heart and is typically caused by bacteria entering the bloodstream and collecting in your heart. A loss of appetite is a common symptom of endocarditis, which means you can lose weight rapidly too. 

The excess inflammation of the condition also causes your metabolism to speed up, so you are burning calories more quickly. Treatment for endocarditis involves medications and sometimes surgery. 

Heart Failure

When your heart is unable to fill with blood or cannot pump blood efficiently, you have congestive heart failure. Sometimes both of these can occur together. 

When your digestive system does not receive enough blood as a result, it can cause a sensation of early fullness, which stops you from eating. Heart failure also causes inflammation, which can speed up your metabolism, also contributing to weight loss. 

Medications are required to restore healthy blood flow. 


Hyperthyroidism is a condition characterized by an overactive thyroid. This gland is responsible for releasing hormones, and when it is hyperactive, your body’s processes also speed up. As a result, more energy is used, and weight loss is common. 

Medications can help to stabilize the activity of the thyroid, and with a balanced diet, you can control weight and prevent further weight loss or damage.

Irritable Bowel Disease (IBD)

This is a collection of digestive disorders that cause chronic inflammation within the digestive tract. Ulcerative colitis and Crohn’s disease are the most common, and each affects a different part of your gut, but inflammation is present in both cases. 

Chronic inflammation causes a more rapid metabolism causing you to lose weight. Your diet is a trigger for these conditions, so you need to avoid foods that cause a reaction, and taking anti-inflammatory medications can help reduce pain and other symptoms.

Grave’s Disease

This is an autoimmune disease that leads to an overactive thyroid (hyperthyroidism). An overactive thyroid gland speeds up your bodily processes, which causes you to burn calories quicker than you consume them. 

Weight loss is a common symptom of Grave’s disease. Treatment involves medications and sometimes surgery to remove the thyroid. 

Rheumatoid Arthritis

This autoimmune disorder causes your immune system to attack your joints in error, resulting in chronic and widespread inflammation. Joint pain, immobility, swelling, and weight loss are common symptoms of rheumatoid arthritis. 

With treatment, you can get the inflammation under control, and while there is no cure for this condition, you can restore joint health and control over your weight.


A stroke occurs when blood flow to the brain is disrupted, and it cannot get the oxygen it needs to function. Weight loss is a common symptom in stroke survivors because changes in the brain may alter mood as well as appetite.

 A stroke can cause impairments physically, so eating can become a challenge. Strokes can also impair your body’s ability to metabolize sugar for energy. It is important to monitor diet and nutrition with stroke patients to ensure they get the nutrients they need. 


Thyroiditis is a general term for conditions that cause inflammation to the thyroid gland. Hashimoto’s thyroiditis is an example of one such condition. 

These conditions cause inflammation, which impacts thyroid function and can cause weight loss as a result of impaired metabolism. Medications and hormone treatments are used to reduce inflammation and correct thyroid function.

Type 1 Diabetes

This autoimmune disease attacks the insulin-producing cells in the pancreas in error. Your body needs insulin to breakdown glucose for energy, and without it, the sugar accumulates in your blood. 

Your kidneys work to remove the excess glucose, and it is excreted along with calories your body needs. This causes weight loss. 

You can treat diabetes successfully with insulin, dietary changes, and glucose monitoring.

When to See Your Doctor

Stressful events and hormonal changes can naturally cause your weight to fluctuate throughout life. So long as the weight loss is not extreme, and you are able to control it, then weight loss is generally harmless. 

If you notice that you are losing weight rapidly and there is no obvious cause, reach out to your doctor. Diagnostic testing can be done to determine if you have a condition that is causing weight loss, and with treatment, you can return to good health.