Understanding Unexplained Weight Loss: Symptoms, Causes, and Treatment Options

How is weight loss defined?

Weight loss means losing any kind of weight. It may be voluntary (the result of dieting) or involuntary.

Cancer Patient

In this case, weight loss is a symptom of potential concern, especially when it is accompanied by a weight loss of at least 10% in less than a year. This threshold is arbitrary but is often used as a “reference” by the medical community (which also sometimes uses the threshold of 5% weight loss in less than 6 months).

Weight loss may be isolated or accompanied by other widely varying symptoms.

When the weight loss is not voluntary, it may be a sign of an underlying, sometimes serious disease, such as cancer.

So it is important to pay attention to it and, if in doubt, consult your doctor. Among other things, your doctor may prescribe blood tests to try to understand the cause.

What are the causes of weight loss?

There are many possible causes of weight loss. In 50% of cases of weight loss, psychological causes can be identified, so a medical examination is necessary. Especially depression often leads to persistent loss of appetite.

Other causes of weight loss have an organic cause, especially digestive diseases. However, a large number of pathologies, for example cardiovascular, endocrine or autoimmune diseases, can also lead to weight loss.

Here is a non-exhaustive list of possible causes of weight loss:

Cancer: Weight loss is common and is often one of the first symptoms. About 40% of people diagnosed with cancer say they have lost weight in the previous months.
Celiac disease: This is often accompanied by weight loss, which is related to the poor absorption of food in the digestive tract.
Gastric ulcers: They are usually responsible for the loss of appetite, stomach pain, and digestive problems that can lead to weight loss.
Crohn’s disease: Along with other inflammatory bowel diseases, Crohn’s disease is often accompanied by weight loss.
Diabetes: It usually involves type 1 diabetes, which manifests as severe dehydration and rapid weight loss.
Heart failure: Although it can lead to fluid retention and thus weight gain, heart failure, especially in advanced stages, can also cause muscle weakness and weight loss.
Infectious disease (HIV infection, hepatitis, tuberculosis, etc.).
Hyperthyroidism: Like other endocrine diseases, disruption of thyroid hormones can affect weight.
Neurological disorders (Alzheimer’s, dementia, Parkinson’s disease, etc.).
Respiratory disease: Chronic obstructive pulmonary disease (COPD) also leads to weight loss.
Abuse of certain substances (drugs, alcohol, or medications) can also lead to weight loss.
Rheumatoid arthritis: Causes chronic inflammation which can speed up the metabolism leading to weight loss.
Dental issues can also lead to weight loss as they can make eating difficult.

In the elderly, loss of appetite is common, leading to sometimes severe malnutrition associated with rapid weight loss.

What are the consequences of weight loss?

Although losing few pounds is often desirable to maintain good health, unintentional weight loss, especially if it persists and reaches a significant threshold, should be a warning sign. They are usually a sign of an underlying, sometimes serious, disease. Severe weight loss can also be a sign of malnutrition, i.e., a deficiency of certain nutrients (for example, in the elderly or in people with digestive diseases).

What can be done to counteract weight loss?

Whether psychological or organic, the cause of weight loss must be identified in order to find solutions or appropriate treatments.

For example, in the case of depression, resuming exercise, the improvement of sleep, and lifestyle habits will help restore appetite when combined with appropriate psychological and pharmacological treatment.

In the case of infectious diseases, antibacterial or antiviral therapies should be started to control the pathogens.

In the case that the weight loss is caused by cancer then a treatment plan should be started that includes drugs to improve appetite in conjunction with cancer-fighting drugs.