Unexplained Weight Loss

Woman weighing herself

There are several reasons you might be losing weight unexpectedly, especially if you aren't trying. If you're experiencing this, talk with your doctor to determine the cause. He or she can have you complete blood test and talk with you about other symptoms you may be having, to come up with a diagnosis.


Certain medications may lead to unintentional weight loss. For example, chemotherapy drugs, thyroid medications, and laxatives are a few examples of medicines that can cause unexpected weight loss. If you've recently starting taking a new medicine, check in with your doctor or pharmacist to see if weight loss one of your medication's side effects.

Type 2 Diabetes

If you have type 2 diabetes and don't know it (uncontrolled diabetes), weight loss can happen, says Cleveland Clinic. Weight loss can occur with diabetes because while your body is taking in plenty of glucose, it isn't able to absorb it into cells properly, and you go into starvation mode. Weight loss may be desirable if you're overweight or obese, but uncontrolled blood sugar (which happens if you have diabetes and aren't getting proper treatment) can be dangerous over time. Other symptoms of type 2 diabetes include extreme urination, excessive thirst, poor wound healing, excessive hunger, itchy skin, and mood changes.


Cancer is another chronic disease that can lead to weight loss, even if you don't have other symptoms. Ask your doctor about lab tests and imaging procedures available to help determine if cancer is indeed the cause of weight loss and to make a cancer diagnosis if that is, indeed, your weight loss culprit.

Chronic Digestive Problems

Digestive diseases can lower the number of calories your body absorbs and when this happens, weight loss can occur. MedlinePlus notes chronic diarrhea, infections like parasites, removal of part of the small intestine (as in the case of weight loss surgery), pancreatic swelling, and infection of the pancreas are all possible causes of unintentional weight loss.

Other Chronic Diseases

Diabetes and cancer aren't the only chronic disease that can lead to unplanned weight loss. Mayo Clinic suggests unexplained weight loss is a symptom of HIV/AIDS, heart failure, thyroid disease, Addison's disease, celiac disease, Parkinson's disease, dementia, chronic obstructive pulmonary disease (COPD), Crohn's disease, dental problems, tuberculosis, peptic ulcers, hypercalcemia (high blood calcium levels), and ulcerative colitis.


If you're feeling stressed, anxious, or depressed, this could be a reason you're unintentionally shedding pounds. Chat with your doctor if you're experiencing symptoms of depression (fatigue, feeling sad, lack of motivation, hopelessness, etc.) or anxiety. If your stress levels are high, attempt to eliminate stressors in your life to see how doing so affects your body weight.

Drug Abuse

Abusing certain drugs (such as amphetamines, cocaine, and alcohol), can lead to unplanned weight loss as well. If you're taking illicit drugs or are drinking heavily, take note of it and cut back or discontinue use to see if unintentional weight loss stops.

Determining a Cause

It's often difficult to determine the cause of unintentional weight loss without seeing a doctor. He or she can run tests that help determine diagnoses, explain why weight loss is occurring, and rule out (or confirm) possible life-threatening diseases like cancer.

When to See a Doctor

If you're feeling off and shedding pounds unintentionally, it's time to chat with a doctor. Cleveland Clinic suggests seeing a medical professional if you lose 10 pounds or more unexpectedly. Mayo Clinic recommends chatting with your doctor if you lose more than 5 percent of your body weight within a 6- to 12-month period.

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Unexplained Weight Loss