Most of us would be happy if we could lose a few pounds without any effort.
But losing weight without eating fewer calories or going to the gym more could be a sign of something malicious.
Rapid weight loss can be a symptom of a number of potentially serious conditions, such as diabetes, stress, serious illnesses and even cancer.
If you unintentionally lose more than five percent of your normal body weight, or more than 10 pounds (4.5 kg) in less than a year, experts say you should see your doctor.
MailOnline investigates why you should never ignore this important health signal.
If you unintentionally lose more than 5 percent of your normal body weight, or more than 10 lbs (4.5 kg) in less than a year, you should see your doctor
An overactive thyroid could be the cause…
An overactive thyroid, medically known as hyperthyroidism, can cause a range of symptoms, including mood swings, muscle weakness, and persistent thirst.
However, an overactive thyroid also causes a spike in metabolism, leading to rapid weight loss. This can also increase your appetite, the NHS explains.
This is because the thyroid gland is responsible for producing hormones that help regulate the body’s metabolism. These hormones are called triiodothyronine (T3) and thyroxine (T4).
Thionamide medications can be used to prevent the thyroid gland from producing too much hormone. However, other treatments, such as radiation therapy to destroy the cells in the thyroid gland, and surgery to remove all or part of the thyroid gland, may also be recommended.
An overactive thyroid also ensures a very good metabolism, which leads to rapid weight loss
Rapid weight loss may indicate type 1 diabetes…
Losing weight despite consuming a lot of calories can also be a symptom of diabetes.
This is because a lack of insulin means that glucose cannot be transported from the blood to the body’s cells to be used as energy.
This causes the body to burn fat and muscle for energy, which can lead to rapid weight loss.
‘Rapid weight loss can be a symptom of type 1 diabetes because one of the main jobs of insulin is to transport sugar from the blood into the cells, where it can be used as energy or stored for later use,’ Esther Walden, senior clinical advisor at Diabetes UK, told MailOnline.
“With no insulin, the cells are starved of energy. The body has to work harder to remove the excess sugar from the blood, but the excess sugar can’t be stored in the fat cells,” she explains.
“Also, when there is no insulin, the body begins to break down fat to produce a form of energy that the body can use,” she said.
She warns that this weight loss can occur quite quickly in the run-up to a diagnosis of type 1 diabetes.
It is a symptom of inflammatory bowel disease.
Crohn’s disease and ulcerative colitis are both forms of inflammatory bowel diseases that cause abdominal pain and diarrhea.
The conditions also cause bleeding from your bottom, blood or mucus in your stool, constant fatigue, and unintentional weight loss.
While it’s not clear what causes these conditions, which affect around 10 million people worldwide, the NHS says they occur when your immune system attacks your gut, causing it to become inflamed.
According to Crohn’s & Colitis UK, it is this inflammation in the gut that prevents your body from fully absorbing the nutrients from your food, leading to weight loss and malnutrition.
It occurs in 80 percent of people with certain cancers and other serious health problems…
Loss of appetite and unintentional significant weight loss are symptoms that affect 80 percent of people with upper gastrointestinal cancer, such as stomach cancer or liver cancer.
‘Sudden and unplanned weight loss can happen if you are going through stressful events in your life, or it may be related to other underlying health conditions,’ Maxine Lenza, health information manager at Cancer Research UK, told this website.
“Unexplained weight loss can also be a symptom of several types of cancer, including lung, colon and pancreatic cancer,” she added.
According to Cancer Research UK, cachexia, also known as wasting syndrome, is a possible symptom of cancer and causes extreme loss of muscle and fat tissue.
People with early-stage cancer do not usually develop cachexia. But up to four in five people with advanced cancer develop some degree of cachexia, the charity explained.
But cachexia is not just a symptom of cancer.
This specific cause of rapid weight loss in cancer can also occur in HIV, kidney disease, and heart disease.
Cancer is thought to be caused by inflammation.
This is because inflammation can cause muscle breakdown and a tumor can take energy from the rest of the body.
Cachexia, also known as wasting syndrome, causes extreme loss of muscle and fat, according to Cancer Research UK
Inflammation has also been linked to muscle loss because it causes proteins to be broken down faster than they are made. That’s because cancer can damage mitochondria, the part of the cell responsible for converting nutrients into energy.
But detecting these cancer symptoms early can make a big difference.
“If you notice any unusual changes, such as losing a noticeable amount of weight without trying, it’s important to talk to your doctor. In most cases, it won’t be cancer, but if it is, catching it early can make a big difference,” Lenza said.
Stress and mental health can be a trigger…
Unintentional weight loss is not only a warning sign of a serious physical illness.
According to the NHS, a stressful life event such as the loss of a loved one, a divorce, a relationship breakdown or losing a job can all contribute to weight loss.
This is because in some cases, stress can cause loss of appetite, indigestion, or repetitive nervous movements.
When you are stressed for a long period of time, stress hormones like cortisol and adrenaline can build up in your body. This can have a variety of physical effects, from disrupted sleep to a loss of appetite.
Adrenaline, the ‘fight or flight’ hormone, usually gives us a boost to motivate us. But too much of it can affect our mood and even our gut, causing stomach cramps and constipation, warns the NHS.
Going through a stressful event such as the loss of a loved one, a divorce, a break-up or losing a job can all contribute to weight loss, the NHS explains
This can make us not feel like eating, which can lead to weight loss.
Weight loss can also result from fidgeting and tapping your feet. If you do this constantly, you can burn extra calories.
Stress isn’t the only mental health condition that can cause rapid weight loss. Depression, anxiety, and eating disorders can also cause a person to lose a lot of weight.
For example, the main symptom of anorexia is that you consciously lose weight or keep your body weight much lower than is healthy for your age and height.
Also, if you lose control over how much you eat and then take drastic measures to avoid gaining weight, this could be a sign of bulimia.
According to the charity Beat, an estimated 1.25 million people in the UK have an eating disorder.
Signs to look out for include: if someone is concerned about their weight or body shape, avoids social occasions involving food, exercises too much and has a strict eating pattern.