Unexplained weight loss refers to a significant drop in overall body weight without making any effort. It isn’t just a slight reduction but involves losing up to 10 pounds or about 5% of body weight over 6 to 12 months. This could be a warning sign of a serious health issue, such as diabetes or cancer. The treatment focuses on identifying and addressing the underlying cause of the condition.
By Able Health I Medically reviewed by Dr. Alireza Estedlal
Page last reviewed: February 2024 I Next review due: February 2026
What is unexplained weight loss?
Unexplained weight loss occurs when body weight significantly drops without any attempt to lose weight. This means you’re losing weight despite not being on a low-calorie diet, changing your eating habits, or increasing your physical activity.
How much weight loss should be concerning?
Unexplained weight loss becomes a concern when you lose over 5% or up to 10 pounds of your body weight within 6 to 12 months, particularly in individuals over 65 years of age. From time to time, everyone tends to gain and lose a little weight, usually within a 5-pound range. However, losing more than this without effort suggests a potential health problem.
Why is unexplained weight loss a warning sign?
Unexplained weight loss is a cause for concern since it is often an indication of various serious underlying conditions that can progress or worsen. Illnesses such as Addison’s disease and diabetes can advance quickly, while others, such as cancers, might develop more gradually. If you notice significant weight loss of over 5% or 10 pounds of overall body weight without any effort, seek medical assistance immediately. Early diagnosis and treatment increase the odds of a full recovery.
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Unexplained weight loss can result from various health problems. While some conditions cause a poor appetite, others hinder calorie absorption or accelerate the rate at which the body burns calories.
These are potential causes of unexplained weight loss:
Addison’s disease: Low cortisol and aldosterone levels can slow metabolism, leading to unexpected weight loss. Other symptoms include chronic diarrhoea, nausea, vomiting, and reduced appetite.
AIDS: In its late stages, AIDS usually causes rapid weight loss due to metabolic changes and chronic diarrhoea.
Cancer: Metabolic or appetite changes associated with cancer can contribute to significant weight loss.
Coeliac disease: Individuals with this condition may lose weight due to the intestines' inability to absorb essential nutrients. Other symptoms include vomiting and diarrhoea.
Crohn’s disease: Inflammation in the colon or bowels may lead to poor appetite and chronic diarrhoea.
Dementia: Advanced dementia can result in problems such as dental issues, swallowing difficulties (dysphagia), reduced appetite, and forgetting to eat, all of which contribute to weight loss.
Dental health problems: Difficulty chewing due to gum disease, cavities, TMJ disorders, or toothaches can result in unexpected weight loss as it becomes harder to eat.
Diabetes: When glucose isn’t available in the cells, the body starts burning fat and muscle for energy. This can occur if diabetes hasn’t been diagnosed or if medication is not managing the symptoms effectively.
Eating disorders: Conditions such as anorexia nervosa or bulimia nervosa can lead to unexpected weight loss.
Heart failure: Late stages of heart failure can sometimes lead to weight loss.
Hyperthyroidism: This disorder accelerates the metabolic rate, leading to weight loss.
Mental health problems: Depression and anxiety can cause appetite changes, often leading to a reduced or absent appetite.
Medications: Some drugs can reduce appetite, alter smell or taste, cause dry mouth, nausea, vomiting, and trouble swallowing, all of which can contribute to weight loss over time.
Parasitic infections: Diarrhoea and vomiting caused by parasitic infections can lead to weight loss.
Pancreatitis: Chronic pancreatitis can reduce appetite and worsen over time.
Parkinson’s disease: Symptoms such as anosmia (loss of smell), swallowing difficulties, depression, nausea, and trouble feeding oneself due to muscle control problems can lead to weight loss.
Peptic ulcer: Appetite loss, nausea, and vomiting associated with peptic ulcers may result in weight loss.
Prescription medicines: Weight loss may be a side effect of some prescription medications.
Ulcerative colitis: Symptoms such as nausea, diarrhoea, and appetite loss can contribute to weight loss.
Substance abuse: Drug and alcohol misuse can alter appetite, cause nausea and vomiting, and ultimately damage the liver.
Diagnosis
What tests are performed to diagnose unexplained weight loss?
Healthcare providers may perform specific tests depending on symptoms, family history, or other factors. For example, an upper endoscopy may be recommended for people with peptic ulcer symptoms.
Common tests for unexplained weight loss include:
Blood tests: These can reveal signs of medical conditions such as coeliac disease, diabetes, or infections, and also provide information about metabolism, adrenal, and thyroid gland function.
Cancer screening tests: Imaging or screening tests may be ordered to rule out cancer. For example, a colonoscopy may be performed to check for colorectal cancer.
Imaging tests: MRI and CT scans can provide detailed images of the brain, lungs, heart, and abdominal organs. One of these imaging tests may be recommended to rule out tumours or illnesses.
Urine test: A urinalysis provides information about the bladder and kidneys and can indicate infections or other medical conditions.
Care and Treatment
What are the treatment options for unexplained weight loss?
Treatment usually depends on the underlying cause. For example, someone with a toothache may need to see a dentist, while a person with a peptic ulcer may require antibiotics. Those with coeliac disease will need to avoid gluten entirely.
How can I treat unexplained weight loss at home?
Do not attempt to treat unexplained weight loss at home. Instead, see a healthcare provider to determine the cause and ensure you receive the appropriate treatment.
Prevention
Is unexplained weight loss preventable?
Most conditions contributing to unexplained weight loss cannot be prevented. However, you can take steps to minimise the risk of some illnesses:
Have an annual physical examination.
Get vaccinated and undergo cancer screenings as recommended.
Take prescribed medications as directed and contact your provider if you experience side effects, such as appetite or weight changes.
Maintain good oral hygiene by brushing twice a day, flossing daily, and seeing a dentist regularly.
Avoid substance misuse and limit alcohol consumption.
When to Call a Doctor
When should I contact my healthcare provider about unexpected weight loss?
It is important to consult your provider if you experience unintentional weight loss, as it may indicate a health problem requiring treatment.
A Note from MD.co.uk
Unexpected weight loss might seem beneficial and easy to overlook, but this symptom should never be ignored. Seek medical assistance for proper diagnosis, as most causes are treatable.
Discuss your symptoms and health history with your provider. One or more tests may be ordered to make a diagnosis, and once the cause is identified, your provider will work with you to develop an appropriate treatment plan. Addressing the underlying problem will help you regain lost weight and feel better.
