We’re not trying to freak you out, but when it comes to all things health, it’s always best to play it safe. Plus, a quick appointment with your doctor will determine if you’re all good, or if there’s need for further testing to pinpoint any underlying causes that warrant medical intervention.
“If you lose 5 to 10 percent of your body weight over the course of three to six months, you need to get checked out,” says Reshmi Srinath, M.D., assistant professor of diabetes, endocrinology, and bone disease at the Icahn School of Medicine at Mount Sinai.
So, for example, if you drop 15 pounds in a matter of months without trying, that’s a sign that something’s not quite right with your health. Meanwhile, if you long ago shunned the scale and notice your clothes becoming baggy, that’s another reason to check in with your primary doc to figure out what’s moving the scale.
Before your appointment, brainstorm any changes that have occurred in your lifestyle, eating habits, or sleep schedule, as well as any symptoms that you’ve been shrugging off, such as fatigue or headaches. These could all be clues to help determine what’s really going on.
Here are nine things that you and your doctor will want to rule out as reasons for your unintended weight loss.
Let’s just go ahead and get the “C” word out of the way. Yes, cancer can lead to rapid weight loss. “If someone reports abrupt weight loss but denies any change in their food intake, their exercise routine, their stress level, and they say their medications have been stable, I would get concerned it was something serious like cancer,” Dr. Srinath says.
Many cancers are associated with a wasting syndrome called cancer cachexia, adds Maya Feller, R.D. “Cancer cachexia is characterized by systemic inflammation, negative protein and energy balance, and an involuntary loss of lean body mass.” It’s most often seen in the later stages of gastric and pancreatic cancers, as well as some lung, head and neck, and colorectal cancers—but if you’ve been ignoring other symptoms and then notice weight loss, you should get to a doctor STAT.
“I have a lot of people who come to me after going through stuff at work or drama with their family or social stressors, and they’ve just stopped eating as much,” Dr. Srinath says. That loss in appetite is tied to the “flight or flight hormones” that your body releases when you’re stressed.
“A structure in the brain called the hypothalamus produces corticotropin-releasing hormone, which suppresses appetite,” explains Feller. “The brain also sends messages to the adrenal glands that sit atop the kidneys to pump out the hormone epinephrine [also known as adrenaline], which helps trigger the body’s fight-or-flight response, a revved-up physiological state that temporarily puts eating on hold.” And if you’ve got no appetite, the pounds are probably going to fall right off.
“Conditions such as celiac disease, Crohn’s disease, lactose intolerance, and intestinal damage will lead to weight loss because they cause malabsorption,” Dr. Srinath says.
Malabsorption is when something prevents your gut from absorbing important nutrients. Gut disease can be easily treated in most cases—like with a gluten-free diet in the case of celiac disease—but you’ll need to go to a gastroenterologist who can confirm the diagnosis.
When people are newly diagnosed with diabetes, they lose a lot of weight.
“The reason for that is their sugars are so high it actually overwhelms their kidneys and their system,” Dr. Srinath says. “They’re not able to use their blood sugar for fuel; it just all gets filtered by the kidneys and excreted. So rather than that sugar going where it needs to go—the muscles, the bones—it’s just lost.”
Typically, people developing diabetes will also experience symptoms like excessive thirst, feeling like they have to pee more often, blurriness in vision, and numbness or tingling in their hands and feet.
Your thyroid controls your metabolism, so it makes sense that thyroid issues could cause weight problems. And while a high metabolism is a plus for weight loss, too high of a metabolism can be unhealthy. “If someone has an overactive thyroid—a disease called hyperthyroidism—they’ll present with rapid weight loss and sometimes additional complications, such as a raised heart rate, more anxiety, jitters and tremors, or insomnia—signs of being more ramped up,” Dr. Srinath says.
Adrenal insufficiency, otherwise known as Addison’s disease, occurs when your body doesn’t produce enough cortisol. Yep, that’s the same cortisol involved in your stress response.
“Under high stress, you produce a ton of cortisol, that’s the normal response,” Dr. Srinath explains. “People who [have] very low cortisol levels can’t have that normal stress response, so they get super sick.”
Adrenal insufficiency typically presents with rapid weight loss, nausea, dizziness, lightheadedness, and more infections, she says.
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Rheumatoid arthritis is a chronic inflammatory disorder affecting your body’s joints, and it just so happens that it can also trigger rapid weight loss. That’s because, in rheumatoid arthritis, pro-inflammatory cytokines not only spur inflammation, but also increase energy expenditure. That means more calories and fat are burned every day, Feller explains. Rheumatoid arthritis most often begins to develop between the ages of 30 and 50.
Reduced appetite and weight loss are common symptoms of depression.
“Some people with depression may experience decreased energy as well as decreased interest in many areas,” says Feller. “This can transfer over to food, resulting in a reduced intake and, in turn, weight loss.”
There are a number of symptoms associated with parasites—especially those that cause gastrointestinal symptoms, which are called helminths and protozoa—says Pascale M. White, M.D., an assistant professor of medicine and director of the gastroenterology clinic at the Icahn School of Medicine at Mount Sinai. “Symptoms can include diarrhea, nausea, vomiting, and lack of appetite,” she says, all of which can contribute to unintended weight loss.