1. Your cycle
  2. Health
  3. Symptoms and diseases

Flo Fact-Checking Standards

Every piece of content at Flo Health adheres to the highest editorial standards for language, style, and medical accuracy. To learn what we do to deliver the best health and lifestyle insights to you, check out our content review principles.

Extreme Weight Loss: Explored and Explained

Unexplained weight loss occurs when you start shedding pounds without making changes to your diet or lifestyle. If your weight loss is extreme or persistent, it may be time to take a closer look. Keep reading for more info on sudden weight loss and how to handle it.

According to experts, you should seek medical attention if you lose more than 5 percent of your total body weight over a period of 6 to 12 months. This is especially important for older adults. 

As an example, if you normally weigh 160 pounds and you’ve lost 8 pounds, that is equal to 5 percent of your overall weight.

Often times, people notice sudden weight loss after undergoing a period of stress. Unintentional weight loss is a pretty common occurrence following divorce, job loss, or bereavement, among other things.

Losing weight too fast could also indicate an eating disorder such as bulimia or anorexia.

Significant and sudden weight loss may create the following problems:

  • Nutritional deficiencies
  • Metabolic disorders
  • Fertility problems 
  • Dysfunctionality of internal organs and systems, including the heart and blood vessels (e.g., irregular heartbeat and poor circulation)
  • Loss of libido or sex drive
  • Difficulty with memory and concentration
  • Nerve and brain issues, including seizures or fits
  • Bowel or kidney problems
  • Weakened immune system
  • Anemia
  • Complications with bones, muscles, hair, and skin 

If you’ve experienced unintentional weight loss of 5 percent or more, be sure to consult your doctor to prevent a serious condition from going undetected. 

In many cases, your general health may decline for a number of medical or non-medical reasons and sudden weight loss is likely to occur. 

Malnutrition is one of the causes of weight loss, and happens when your diet lacks the proper nutrients. Never ignore the symptoms of unexplained weight loss, especially if they’re accompanied by:

  • Fatigue
  • Reduced appetite
  • Increased frequency of infections or other illnesses
  • Constipation or diarrhea

Other typical explanations for unintentional weight loss are:


A type of mood disorder in which you experience constant feelings of sadness and loss of interest. Signs of depression include:

  • Feeling melancholy, sad, tearful, or hopeless
  • Having sleep disturbances (e.g., struggling with insomnia or oversleeping)
  • Loss of pleasure or interest in activities you previously enjoyed like sports, hobbies, or sex
  • Fatigue or tiredness
  • Decreased appetite leading to extreme weight loss
  • Feelings of worthlessness that produce suicidal thoughts or attempts 

Hyperthyroidism or hypothyroidism

Extreme weight loss is occasionally attributed to hyperthyroidism (an overactive thyroid) or hypothyroidism (an underactive thyroid). 

In hyperthyroidism, your thyroid gland secretes excessive amounts of hormones, causing symptoms that require medical treatment. They include: 

  • Anxiety, irritability, and nervousness
  • Mood swings
  • Extreme weight loss
  • Goiters (i.e., enlargement of the thyroid gland producing neck swelling)
  • Palpitations (i.e., unusually fast and/or irregular heart rate)


Characterized by uncontrollable growth and reproduction of cells in a particular region of your body, cancer is capable of triggering unexplained weight loss. Cancer cells may spread to surrounding healthy tissues and destroy them. Depending on their location, they’re responsible for a wide array of symptoms.

Addison’s disease

In rare cases, unintentional weight loss could be blamed on a disorder of your adrenal glands. Their failure to secrete enough cortisol and/or aldosterone produces symptoms like:

  • Fatigue
  • Muscle weakness 
  • Poor mood and low energy
  • Reduced appetite and a tendency towards losing weight without trying
  • Increased thirst

Such symptoms might gradually become severe and be accompanied by cramps, exhaustion, dizziness, and fainting.


Diabetes is a chronic medical condition in which your blood glucose levels become elevated, perhaps accounting for unintentional weight loss. It’s the result of either reduced secretion of insulin by your pancreas or your body’s inability to respond to insulin. Signs of diabetes include:

  • Increased thirst
  • Frequent urination, especially at night
  • Fatigue
  • Unintentional weight loss
  • Reduced muscle mass

Crohn’s disease

It’s a type of inflammatory bowel disease (IBD) that causes inflammation of your digestive tract. The exact location of inflammation varies by individual. Among its symptoms are severe diarrhea, abdominal pain, extreme weight loss, fatigue, and malnutrition. 

Celiac disease

Celiac disease is another possible rapid weight loss cause characterized by a reaction of your immune system to gluten consumption. Gluten is a protein present in barley, rye, and wheat.

Irritable bowel syndrome (IBS)

IBS commonly affects your large intestine, with its most common signs and symptoms being:

  • Pain in the abdomen, cramping, and bloating which is partially or completely relieved by bowel movements
  • Excess formation of gas
  • Presence of mucus in the stool
  • Constipation or diarrhea (in some cases, they alternate)


Anorexia is a type of eating disorder which leads to excessively low body weight and fosters an intense, potentially life-threatening fear of gaining weight. Surprisingly, this disorder isn’t usually food-related, but rather a coping mechanism for dealing with emotional problems. Anorexia has various behavioral, emotional, and physical side effects, including extreme weight loss.

What are some other plausible explanations for unintentional weight loss?

  • Adverse effects of taking certain medications
  • Drug or alcohol abuse
  • Dental issues like tooth loss and mouth ulcers or getting new braces or implants
  • A viral, parasitic, or bacterial infection (e.g., gastroenteritis, HIV, AIDS, or tuberculosis (TB)
  • Gut problems

Slight fluctuations in body weight are usually considered normal. However, unexplained weight loss of more than 5 percent in 6 to 12 months could point to a larger issue. Please see a doctor if you observe any of the symptoms mentioned above.

Sudden and unexplained weight loss may be brought on by anything from stress and eating disorders to depression and diabetes. It can produce nutritional deficiencies, anemia, metabolic disorders, fertility problems, etc. That’s why it’s important to consult your doctor regarding any significant unintentional weight loss.














Read this next