15 Reasons Behind Unexplained Weight Loss

unexplained weight loss

15 Reasons Behind Unexplained Weight Loss4 min read

Unexplained weight loss can represent the chiming of church bells in one’s mind. But in other cases it can be more concerning. That’s why we have put together a list of 15 reasons behind unexplained weight loss and why it might be more serious than you think.

But first, let’s get into the definition of unexplained weight loss. As stated in a 2018 article published by Mayo Clinic, unexplained weight loss is the ”losing weight without trying — particularly if it’s significant or persistent.”

Symptoms are generally not concerning unless the individual looses more than 5% of their weight in less than 6 months time. To put this in perspective, this means that a person weighing 160 pounds must loose 8 pounds in total to categorize their symptoms as unexplained weight loss. 

Now let’s get serious. 

unexplained weight loss

A Few Reasons for Unexplained Weight Loss

1. Endocrine conditions

Conditions such as hyperthyroidism (overactive thyroid), hypothyroidism (underachieve thyroid), diabetes, and Addison’s disease.

2. Infections

This includes viruses and bacteria that have entered the bloodstream, HIV/AIDS, tuberculosis, and endocarditis, etc.

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3. Cancer

As stated in a 2018 article published by Very Well Health: ”Weight loss may be the first sign of blood-related cancers such as leukemias and lymphomas, or solid tumors such as lung cancer (especially adenocarcinoma of the lung), colon cancerovarian cancer and, pancreatic cancer. Weight loss can also occur when an early stage tumor (such as breast cancer) recurs.”

4. Intestine problems

This includes peptic ulcer disease, celiac disease, Crohn’s disease, ulcerative colitis, and pancreatitis.

5. Heart failure

As stated in a 2018 article published by Cardio Heart:‘It is believed that reduced blood flow may be closely associated with debilitating heart failure symptoms, such as nausea and weight loss. Unintentional weight loss is a serious complication of heart failure, especially in patients with severe heart failure.”

unexplained weight loss

6. Kidney failure

Otherwise known as Chronic Kidney Disease, most symptoms, as reported by Healthline, are not noticeable until the kidney is already deteriorating. Some symptoms of CKD include weight loss, muscle pain, urine-like smelling breathe, and even brittle hair and nails.

To get the full insight on kidney failure visit this article here.

7. Oral concerns

Surprised aren’t you? This generally includes gum disease and tooth decay.

To get the full insight on gum disease visit this article here.

8. Smoking

9. Eating disorders

This generally includes anorexia nervosa and bulimia. Although both conditions should be defined by individual case, the most common definitions of these diseases are as followed:

Anorexia nervosa: Forcing oneself to diet or simply not eating enough.

Bulimia: The phycological idolization towards ”thinness” and ”looking thin.” Such symptoms would include forcing oneself to vomit after eating (purging), excessive dieting, and extreme lack of body confidence.

To learn more about these disorders visit this article here.

10. Poor nutrition

This is self-explanatory. If you are receiving less calories than you are putting out (while exercising or dieting) you are bound to experience unhealthy weight loss.

This is also why it is important to check with your doctor for a second opinion before implementing a new diet plan that will directly impact your physical and physiological attributes. Forms of fasting, especially, can lead to detrimental results if not practiced safety.

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11. Physiological conditions

This would include depression and anxiety.

12. Medication

As stated in an article published by Very Well Health ”Nearly any medication may have weight loss as a considered side effect.  Medications may cause weight loss directly, or cause nausea and loss of appetite leading to weight loss.”

13. Drug abuse

And this doesn’t just include those ”street drugs” like methamphetamines but even over-the-counter-drugs such as laxatives.

14. Neurological conditions

Mainly seen in older individuals, such symptoms include the diagnosis of Alzheimer’s and Parkinson’s disease.

15. Peptic ulcer disease

As stated by Reader’s Digest Peptic Ulcer Disease occurs when ”open sores develop on the inside lining of the stomach as well as on the upper portion of the small intestine.”

It is important to note that it is the medications which relieve PUD are the main culprits of weight loss and not so much the disease itself.


Our conclusion? The reasons behind unexplained weight loss provide more questions than answers. As always we highly suggest being diagnosed by your doctor before assuming you have one of the aforementioned conditions.

This article itself is meant to serve as an educational guide on the reasons behind unexplained weight loss, not a doctor’s note. 

unexplained weight loss
unexplained weight loss
unexplained weight loss

M. G. Hughes is a novelist and content creator. Born and raised in San Diego, aside from writing she also enjoys cinematography, interior design, and hiking.