Unexplained Weight Loss



What is unexplained weight loss?

Unexplained weight loss, or losing weight without trying — particularly if it’s significant or persistent — may be a sign of an underlying medical disorder.

The point at which unexplained weight loss becomes a medical concern is not exact. But many doctors agree that a medical evaluation is called for if you lose more than 5 percent of your weight in six months to a year, especially if you’re an older adult. For example, a 5 percent weight loss in someone who is 72 kilograms is 3.6 kilograms. In someone who is 90 kilograms, it’s 4.5 kilograms.

Your weight is affected by your calorie intake, activity level, overall health, age, nutrient absorption, and economic and social factors.

How common is unexplained weight loss?

Unexplained weight loss is common. It can occur in patients in any gender at any age. It can be managed by reducing your risk factors. Please discuss with your doctor for further information.

Which signs and symptoms can unexplained weight loss usually be associated with?

Related signs and symptoms include:

  • Muscle loss
  • Muscle weakness
  • Fast, irregular heart rate
  • Anxiety
  • Fatigue
  • Heat intolerance
  • Sleep troubles
  • Hand tremors
  • Light periods in women
  • Frequent urination
  • Dehydration
  • Fatigue
  • Blurry vision
  • Excessive thirst
  • Excessive hunger
  • Constant sadness
  • Loss of interest in hobbies
  • Low energy
  • Poor concentration
  • Sleeping too little or too much
  • Thoughts of death or suicide
  • Irritability
  • Diarrhea
  • Stomach pain
  • Bloating
  • Bloody stools
  • Fatigue
  • Shortness of breath
  • Wheezing
  • Chest tightness
  • Mild coughing, with or without mucus


What causes unexplained weight loss?

Causes of unexplained weight loss can include:

  • Muscle loss. Muscle loss, or muscle wasting, can lead to unexpected weight loss. The major symptom is muscle weakness. One of your limbs may even look smaller than the other. Your body is made of fat mass and fat-free mass, which includes muscle, bone, and water. If you lose muscle, you’ll lose weight. This can happen if you don’t use muscles for a while. It’s most common in people who don’t exercise, work desk jobs, or are bedridden. Generally, exercise and proper nutrition will reverse muscle loss.
  • Overactive thyroid. Hyperthyroidism, or overactive thyroid, develops when your thyroid gland makes too much thyroid hormone. These hormones control many functions in the body, including metabolism. If your thyroid is overactive, you’ll quickly burn calories even if you have a good appetite. The result can be unintentional weight loss.
  • Rheumatoid arthritis. Rheumatoid arthritis (RA) is an autoimmune disease that makes your immune system attack the lining of your joints, leading to inflammation. Chronic inflammation can speed up metabolism and reduce overall weight.
  • Another cause of unwanted weight loss is type 1 diabetes. If you have type 1 diabetes, your immune system attacks cells in your pancreas that make insulin. Without insulin, your body can’t use glucose for energy. This causes high blood glucose. Your kidneys remove unused glucose through urine. As sugar leaves your body, so do calories.
  • Weight loss may be a side effect of depression, which is defined as feeling sad, lost, or empty for at least two weeks. These emotions interfere with daily activities, such as going to work or school. Depression affects the same parts of the brain that control appetite. This can lead to poor appetite, and eventually, weight loss.
  • Inflammatory bowel disease. Unexpected weight loss may be a symptom of inflammatory bowel disease (IBD). IBD is a term that encompasses several chronic inflammatory disorders of the digestive tract. The two most common types are Crohn’s disease and ulcerative colitis. The chronic inflammation of IBD puts your body in a catabolic state, which means that it’s constantly using up energy. IBD also disrupts ghrelin, the hunger hormone, and leptin, the satiety hormone. This results in decreased appetite and weight loss.
  • Chronic obstructive pulmonary disease. Chronic obstructive pulmonary disease (COPD) is a progressive lung disease. This includes emphysema and chronic bronchitis. Many people with COPD have both. Emphysema slowly damages the air sacs in your lungs, making it hard to breathe. Chronic bronchitis causes inflammation of the airways that bring air to your lungs. This produces mucus, coughing, and breathing issues. In later stages, COPD can cause weight loss. Labored breathing burns a lot of calories.
  • Endocarditis causes inflammation of your heart’s inner lining, or endocardium. It develops when germs —usually bacteria — enter the bloodstream and collect in your heart. Most people with endocarditis have a fever. This may come along with a poor appetite. Elevated body temperature also increases metabolism and burns fat, causing weight loss.
  • Another cause of unexplained weight loss is tuberculosis (TB), a contagious condition that usually affects the lungs. It’s caused by Mycobacterium tuberculosis bacteria. Weight loss and decreased appetite are major symptoms of TB, but the reasons aren’t fully understood.
  • Cancer is the general term for diseases that cause abnormal cells to quickly divide and spread. According to the American Cancer Society, one of the first signs may be unexplained weight loss. This is common with cancers of the pancreas, lung, stomach, and esophagus.
  • Addison’s disease. Addison’s disease develops when the immune system attacks the adrenal glands. In turn, the adrenal glands can’t make enough hormones like cortisol and aldosterone. Cortisol regulates many functions, including metabolism and appetite. Low levels of cortisol may lead to poor appetite and weight loss.
  • HIV attacks immune cells called T cells. This makes it difficult to fight infections. If left untreated, HIV can lead to acquired immunodeficiency syndrome (AIDS). Advanced forms of these conditions often cause weight loss.
  • Congestive heart failure. Weight loss is a complication of congestive heart failure (CHF). CHF develops when the heart can’t fill up with enough blood, the heart can’t pump blood with enough force, or both. It may affect one or both sides of the heart. If you have CHF, your digestive system can’t receive enough blood. This can lead to nausea and early fullness. Additionally, it might be hard to breathe while eating. The inflammation in damaged heart tissue also speeds up metabolism, causing unintentional weight loss.

The conditions mentioned above are some common causes of unexplained weight loss. Consult with your doctor for an accurate diagnosis.

Risk factors

What increases my risk for unexplained weight loss?

Unexplained weight loss can occur in anyone. However, it is most common (and most serious) in people who are over the age of 65. Even unexplained weight loss of less than 5 percent of body weight may be the sign of a serious condition in older people.

Please consult with your doctor for further information.

When to see your doctor

When should I see my doctor?

If you’re losing weight without trying and you’re concerned about it, consult your doctor — as a rule of thumb, losing more than 5 percent of your weight within six to 12 months may indicate a problem. If you’re an older adult with many or more-serious underlying health issues, even a smaller amount of weight loss may be significant. Your doctor will work with you to try to determine what’s causing the weight loss. At first that will involve a thorough history, a physical examination and basic laboratory testing. Imaging scans to look for hidden cancers are not usually helpful unless some other clue points in that direction.

Sometimes, if the basic evaluation is negative, watchful waiting for one to six months is a reasonable next step. You may need a special diet to prevent further weight loss or to regain lost weight.

On noticing one of these symptoms or having any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor to get the best solutions for your situation.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage unexplained weight loss?

These following lifestyles and home remedies might help you cope with unexplained weight loss:

  • Use nutrition shakes to get more calories
  • Add flavor enhancers to your food to improve the taste so that you eat more
  • Visit a dietitian for advice and counseling

If you have any questions, please consult with your doctor for the best solutions.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: January 16, 2019 | Last Modified: January 16, 2019

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