When weight loss occurs without any conscious changes made in lifestyle, physical activity, or diet, it is termed unintentional weight loss. A certain amount of fluctuation in weight is natural. However, unintentional weight loss is considered concerning or significant in the following situations:
- If more than 5% of one’s weight is lost within 6-12 months.
- Weight loss is obviously visible to oneself and others
- There is accompanying weakness, fatigue, and loss of work capacity
CAUSES
In case of unintentional weight loss that is significant and concerning, it is important to find the cause and rule out certain underlying medical conditions.
Psychological
Often, there is a psychological issue underlying unintentional loss of weight. This can include depression, anxiety, and stress. Eating disorders like anorexia nervosa should also be evaluated for in younger patients.
Reduced sleep is also a very important, often overlooked cause.
Neurological
Especially with aging, neurological conditions like dementia or Alzheimer’s, Parkinson’s disease, or a stroke should also be evaluated for.
Metabolic
Weight loss can be a presentation of diabetes, which should always be ruled out.
Thyroid disorders, especially hyperthyroidism, may be another common cause that may present with other symptoms like palpitation, tremor, heat intolerance, etc. Other endocrine disorders may be rarely the reason like adrenal insufficiency, etc.
Digestive
Improper digestion and absorption of nutrients, due to conditions of the gastrointestinal (GI) system, can often lead to weight loss. This can include inflammatory bowel disease (IBD – Crohn’s disease and ulcerative colitis), malabsorption syndromes (like sprue, coeliac disease), food allergies, chronic or recurrent GI infections, irritable bowel syndrome (IBS) with diarrhea, acidity, and peptic ulcers,
GI obstruction or stricture, swallowing difficulty (dysphagia), or dental problems, including mouth ulcers, etc. Liver disease, as well as gall bladder inflammation and stones, or chronic pancreatitis, can also be a cause.
Symptoms like abdominal pain, diarrhea, vomiting, indigestion, loss of appetite, etc. should be enquired for, and sometimes GI imaging by ultrasound or endoscopy may be needed.
Infections
Tuberculosis (TB) is one of the common causes of weight loss in developing countries like India, and should be investigated for in all cases of unintentional weight loss.
HIV infection can manifest as weight reduction before any other symptom, so it should always be tested for and ruled out.
Sometimes respiratory tract infections like flu, recurrent cold, cough, and COVID, as well as recurrent urinary tract infections (UTI), can also lead to weight loss.
Chronic Conditions or Comorbidities
Certain chronic conditions of the heart and lung can often be associated with weight loss, such as heart failure, chronic obstructive pulmonary disease (COPD), and interstitial lung disease (ILD).
Chronic liver and kidney disease can also be associated causes.
Drug, Medicines, or Substance Abuse
This is one of the most common causes that include too much intake of alcohol, narcotic drugs, or even prescription drugs like antibiotics, painkillers, antidepressants (SSRI/SNRI), diabetic drugs like GLP-1/metformin, etc.
Electrolyte levels
Low sodium or high calcium levels are both underlying associations with weight loss.
Cancer
Any malignancy or tumor in the body can lead to weight loss, and this may sometimes be the only visible or early symptom of the cancer. A high index of suspicion with regard to lifestyle, personal and family history, age, and other risk factors will help pick up cancers early. Recommended cancer screening tests also help.
Autoimmune and other conditions
Conditions like lupus, rheumatoid arthritis, and other autoimmune conditions can be rarer causes of loss of weight. One must enquire about other symptoms. A relatively rare condition called amyloidosis, which is the build-up of abnormal amyloid deposits in the body organs like the heart, brain, kidneys, spleen, etc., can also manifest as weight loss.
Note: Cachexia is a term used to describe ill health involving marked weight loss, characterized by muscle mass loss.
MANAGEMENT
HISTORY: A complete history of diet, lifestyle, physical activity, personal medical history, family history, and a detailed enquiry into accompanying symptoms is taken by the physician. Menstrual history in women must be enquired for as weight loss in women may be associated with both period problems or menopause.
PHYSICAL EXAMINATION: Thereafter, a thorough physical examination is important, including weight/height check, blood pressure, mouth examination, chest auscultation, abdominal examination, and looking for enlarged lymph nodes or swellings.
PSYCHOLOGICAL EVALUATION: This is often overlooked but very important. In the elderly, it is often the main cause of weight loss. This should include mood, stress, sleep, and cognition.
INVESTIGATIONS: All routine blood investigations should be done, including complete blood counts, sugar check, kidney and liver function tests, lipid profile, thyroid function tests, blood proteins and electrolytes, and age-appropriate markers of cancer or autoimmune and other diseases when clinical suspicion is present. Specific blood tests for HIV, TB, and other infections, when suspected, may also be performed. A urine and stool test may also be ordered. A chest X-ray is routinely performed, and when necessitated by history and symptoms, additional imaging tests like ultrasound, endoscopy, or CT/MRI may be ordered.
TREATMENT: This is usually done by treating the underlying condition with supportive nutritional and psychological care. Therefore, management requires a holistic approach with a multispecialty team of a physician (with specialists depending on clinical condition – cardiologist, pulmonologist, neurologist, gastroenterologist, oncologist, etc.), along with a nutritionist, physical therapist, and psychologist.
See the ideal weight calculator for reference
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