Weight loss: Causes, Symptoms and Diagnosis

Suffering from Unexplained Weight loss? Know all the reasons here.

HEALTH

7/22/20242 min read

person standing on white digital bathroom scale
person standing on white digital bathroom scale

Unexplained weight loss refers to a significant drop in body weight that occurs without intentional efforts like diet, exercise, or lifestyle changes. Losing 10 pounds or more, or five percent of body weight, within 6 to 12 months is considered “unexplained.” This can signal a serious underlying condition or illness, so it's crucial to seek medical attention if you experience such weight loss.

Causes of Unexplained Weight Loss

1. Cancer

  • Symptoms: Unexplained weight loss often accompanies cancers of the esophagus, stomach, pancreas, and lungs. Ovarian cancer may cause weight loss when a tumor presses on the stomach, causing a feeling of fullness.

  • Mechanism: Cancer can cause nausea, lack of appetite, and difficulty eating. It also increases inflammation, disrupting hormones that regulate appetite and leading to fat and muscle breakdown.

  • Diagnosis: Tests like ultrasound, CT scans, tumor marker tests (CEA, CA-125), chest X-rays, upper endoscopy, and biopsy help in diagnosing cancer.

2. Hyperthyroidism

  • Symptoms: Hyperthyroidism occurs when the thyroid gland produces too much hormone, speeding up metabolism. This can cause weight loss, hand tremors, and a rapid or irregular heartbeat.

  • Diagnosis: Thyroid function tests (T3, T4, TSH), Anti-TPO antibodies, and iodine uptake scans can confirm hyperthyroidism.

3. Uncontrolled Diabetes

  • Symptoms: In type 1 diabetes, the body can't use sugar for energy due to lack of insulin, leading to weight loss as sugar is excreted in urine.

  • Diagnosis: Blood tests like HbA1c and blood sugar levels (fasting and postprandial) are used to diagnose diabetes.

4. Tuberculosis (TB)

  • Symptoms: TB, an infectious disease affecting the lungs, causes prolonged cough (sometimes with blood), chest pain, weakness, fatigue, weight loss, fever, and night sweats.

  • Diagnosis: Rapid diagnostic tests like Xpert MTB/RIF Ultra and Truenat assays, along with tuberculin skin tests (TST) or interferon-gamma release assays (IGRA), help detect TB.

5. Chronic Inflammatory Diseases

Chronic inflammation can lead to various conditions, each affecting body weight differently.

  • Rheumatoid Arthritis (RA): Inflammation in joints increases metabolism and muscle wasting, leading to weight loss.

  • Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis cause malabsorption of nutrients due to intestinal inflammation.

  • Chronic Obstructive Pulmonary Disease (COPD): Inflammation in the lungs increases energy expenditure and muscle wasting.

  • Lupus (SLE): Inflammation in multiple organs and medication side effects affect metabolism and appetite.

  • Chronic Kidney Disease (CKD): Long-term kidney inflammation leads to protein-energy wasting.

Mechanisms Linking Chronic Inflammation to Weight Loss

  • Increased Metabolic Rate: Chronic inflammation can increase the body's resting metabolic rate, leading to greater energy expenditure.

  • Appetite Suppression: Pro-inflammatory cytokines can affect the brain's appetite-regulating centers, reducing hunger.

  • Muscle Wasting: Inflammation can promote muscle breakdown, leading to loss of muscle mass.

  • Malabsorption: In conditions like IBD, inflammation can damage the gastrointestinal tract, impairing nutrient absorption.

6. Depression

  • Symptoms: Depression causes persistent sadness and lack of interest in activities, often leading to unintentional weight loss.

  • Mechanism: Neurotransmitter imbalances reduce appetite and pleasure from eating, and chronic stress elevates cortisol levels, increasing metabolic rate. Depression also disrupts the gut-brain axis, causing gastrointestinal issues that reduce food intake.

  • Diagnosis: Scales like the Hamilton Depression Rating Scale (HDRS) and Beck Depression Inventory (BDI) are used to assess the severity of depression.

Conclusion

Unexplained weight loss can be a symptom of various serious conditions. It's essential to consult a healthcare provider to identify the underlying cause and receive appropriate treatment. Regular monitoring and timely medical intervention can help manage these conditions effectively.