Unexplained Weight Loss

Unexplained Weight Loss: What are the Possible Causes?

Unexplained weight loss is a phenomenon that should alert you to your general health. If you are losing weight for no apparent reason, it is important to understand the potential causes of this problem and address them. Our general practitioners explain to you what is the most common cause of unexplained weight loss, as well as methods of diagnosis and treatment.

What is Unexplained Weight Loss?

Unexplained weight loss refers to a significant decrease in body weight for no apparent reason, such as a change in diet or an increase in physical activity. It is necessary to weigh yourself regularly to detect weight loss, because weight loss that occurs over several months, or in obese people, can sometimes be difficult to detect. Losing a few pounds naturally may be normal, but significant, unexplained weight loss may indicate an underlying health problem.

What are the Possible Causes of Unexplained Weight Loss?

Whether physical or mental, there are many reasons that can explain weight loss.

Gastrointestinal Diseases

Gastrointestinal diseases such as celiac disease , Crohn’s disease , functional colopathy , and ulcerative colitis can lead to weight loss. These inflammatory bowel pathologies affect the body’s ability to absorb nutrients, which can lead to a reduction in body weight.

Hormonal Problems

Hormonal disorders , such as those of the thyroid like hyperthyroidism , can speed up metabolism and lead to unexplained weight loss. Likewise, uncontrolled diabetes can also cause unintentional weight loss.


Unexplained weight loss can be an early symptom of certain types of cancer , such as lung cancer , pancreatic cancer , and stomach cancer. This may be due to several factors such as the increase in the body’s energy expenditure to fight the disease, the reduction in the feeling of hunger linked to the release of hormonal factors by the tumor or even taste abnormalities.

Stress and Anxiety

Chronic stress and anxiety can impact appetite and lead to unexplained weight loss . People under severe stress may lose their appetite and may not consume enough calories to maintain normal body weight.


Depression can affect appetite and motivation to take care of yourself, which can lead to weight loss . People with depression may experience a decreased interest in food as well as a loss of appetite.

Eating Disorders

Eating disorders or eating disorders (EDBs) such as anorexia and bulimia can lead to unexplained weight loss. These disorders are often associated with disordered eating behaviors that disrupt calorie balance and cause weight loss.

Drug Side Effects

Some medications can cause unintentional weight loss by disrupting appetite or metabolism. For example, painkillers, antidepressants and medications used to treat certain chronic illnesses can have this side effect. Ingestion of toxic substances, such as chronic alcoholism, is also a cause of significant weight loss.

Chronic Diseases

Certain chronic illnesses, such as kidney failure, heart failure, and chronic obstructive pulmonary disease (COPD), can lead to unexplained weight loss. These diseases affect the normal functioning of the body, including metabolism, which can lead to a decrease in body weight.

Infectious Diseases

Any infectious disease, whether viral, bacterial, parasitic or mycotic, can cause weight loss, most often associated with fever, reflecting the body’s energy expenditure to fight against the disease. If weight loss is significant, you should look for certain infections such as respiratory infections or HIV.

What to do in Case of Unexplained Weight Loss?

If you are experiencing unexplained weight loss, it is important to consult your primary care physician for an accurate diagnosis and appropriate treatment. Your doctor will be able to carry out a complete assessment of your state of health, which may include additional medical examinations such as blood tests and a hormonal assessment to identify potential underlying causes.

Treatment for unexplained weight loss will depend on what’s causing it. In some cases, diet and lifestyle changes may be enough to resolve the problem. In other cases, medical treatment or psychotherapy may be necessary to treat the underlying cause.

Can We Prevent Unexplained Weight loss?

It is not always possible to prevent unexplained weight loss, as it may be due to medical or psychological factors beyond our control. However, maintaining a healthy lifestyle, eating a balanced diet and exercising regularly can help maintain a stable body weight and reduce the risk of unintentional weight loss. If you notice that you are losing weight over the past few weeks, don’t wait to consult a health professional. If your GP is not available, our general practitioners can receive you by teleconsultation every day from 6 a.m. to midnight.

What Noble Health Clinic can do for You?

Are you experiencing symptoms or simply want to speak to a specialist for medical advice? With Noble Health Clinic, obtain a medical diagnosis in just a few minutes, 7 days a week, as well as an electronic prescription valid in the pharmacy.

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