Why Losing 10 Pounds in a Week Without Trying Is a Warning Sign

If you’ve been actively working to lose weight and seeing results, that’s fantastic news. It indicates your efforts are aligned with your goals. However, if you find yourself losing weight unexpectedly and without making any intentional changes, it’s not typically a cause for celebration. Your body weight acts as a crucial indicator of your overall health, and significant, unintended weight fluctuations could signal an underlying issue that warrants attention.

Taking a moment to understand this is important, not to cause alarm, but to empower you with knowledge. In health matters, prioritizing safety and seeking professional guidance is always the best approach. A consultation with your doctor can quickly determine if everything is fine or if further investigation is needed to identify any potential causes that require medical intervention. It’s a straightforward step towards peace of mind.

According to Reshmi Srinath, M.D., assistant professor of diabetes, endocrinology, and bone disease at the Icahn School of Medicine at Mount Sinai, “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.” For example, if someone weighing 150 pounds drops unexpectedly to 135 pounds within a few months, that’s a significant sign that something might not be right with their health. Similarly, if you haven’t weighed yourself in a while but notice your clothes becoming noticeably looser or baggy, it’s another prompt to consult with your primary care physician to understand what’s causing the scale to drop.

Before your appointment, it can be helpful to reflect on any recent changes in your lifestyle, including shifts in eating habits, sleep patterns, or stress levels. Also, consider any other symptoms you might have been experiencing but perhaps dismissing, such as persistent fatigue or headaches. These details can serve as valuable clues to help you and your doctor pinpoint the root cause of the unintended weight loss.

Here are nine potential reasons that you and your healthcare provider will likely consider and rule out as contributing factors to your unexpected weight loss.

Cancer

Addressing one of the most serious possibilities upfront, cancer can indeed lead to rapid and unexplained weight loss. Dr. Srinath notes, “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.” Maya Feller, R.D., adds that many cancers are associated with a condition known as cancer cachexia, a wasting syndrome. Cachexia, she explains, “is characterized by systemic inflammation, negative protein and energy balance, and an involuntary loss of lean body mass.” While it’s most frequently observed in advanced stages of certain cancers like gastric, pancreatic, lung, head and neck, and colorectal cancers, experiencing unexplained weight loss, especially alongside other ignored symptoms, should prompt immediate medical evaluation.

Stress

High levels of psychological stress are a common culprit for unintentional weight loss. Dr. Srinath observes, “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.” This reduction in appetite is often linked to the body’s “fight or flight” response hormones released during stressful periods. Feller elaborates, “A structure in the brain called the hypothalamus produces corticotropin-releasing hormone, which suppresses appetite.” She adds, “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.” With a suppressed appetite and potentially skipping meals, losing weight without trying can become a reality.

Woman doing a yoga pose for stress relief to help manage stress

Gut Disease

Conditions affecting the digestive system can significantly impact nutrient absorption and lead to weight loss. Dr. Srinath states, “Conditions such as celiac disease, Crohn’s disease, lactose intolerance, and intestinal damage will lead to weight loss because they cause malabsorption.” Malabsorption occurs when the gut is unable to properly absorb essential nutrients from food. Many gut diseases are manageable with appropriate diagnosis and treatment, such as adopting a gluten-free diet for celiac disease. However, confirming the diagnosis typically requires consultation with a gastroenterologist. If you’re considering changes to your diet, especially if you are a losing a lot of weight while breastfeeding, it’s always best to consult a professional.

Diabetes

Interestingly, when individuals are first diagnosed with diabetes, particularly type 1 or sometimes type 2 that has been uncontrolled, they often experience significant weight loss. Dr. Srinath explains, “The reason for that is their sugars are so high it actually overwhelms their kidneys and their system.” She continues, “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.” In addition to weight loss, common symptoms signaling the development of diabetes can include excessive thirst, frequent urination, blurred vision, and tingling or numbness in the hands and feet.

Thyroid Disease

The thyroid gland plays a critical role in regulating your body’s metabolism, meaning thyroid disorders can directly impact weight. While a slightly elevated metabolism might be beneficial for intentional weight loss, an excessively high metabolic rate due to an overactive thyroid can be detrimental to health. Dr. Srinath notes, “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.” If you are a feeding mother looking for an easy way to lose weight while breastfeeding, thyroid health is one factor that a doctor might assess alongside dietary considerations.

Adrenal Insufficiency

Also known as Addison’s disease, adrenal insufficiency occurs when the adrenal glands do not produce sufficient amounts of cortisol, a hormone crucial for the body’s stress response. Dr. Srinath clarifies the role of cortisol: “Under high stress, you produce a ton of cortisol, that’s the normal response.” She adds that individuals with very low cortisol levels “can’t have that normal stress response, so they get super sick.” Adrenal insufficiency is typically characterized by rapid weight loss, along with other symptoms like nausea, dizziness, lightheadedness, and increased susceptibility to infections.

Rheumatoid Arthritis

Affecting approximately 1 to 3 percent of women, rheumatoid arthritis is a chronic inflammatory disorder primarily targeting the body’s joints. Beyond joint issues, it can also contribute to sudden weight loss. Feller explains that in rheumatoid arthritis, pro-inflammatory cytokines not only fuel inflammation but also boost energy expenditure. This means more calories and fat are burned daily. Rheumatoid arthritis often begins to manifest between the ages of 30 and 50. For a diet plan for weight loss for feeding mothers, considering underlying inflammatory conditions is part of a comprehensive health assessment.

Depression

Mental health conditions, such as depression, can significantly impact physical health, and reduced appetite and subsequent weight loss are common symptoms. Feller states, “Some people with depression may experience decreased energy as well as decreased interest in many areas.” She adds that this can extend to eating, “resulting in a reduced intake and, in turn, weight loss.” When focusing on managing weight or trying to lose weight without losing milk supply, addressing mental health is a crucial component of overall well-being.

Parasites

Certain parasitic infections, particularly those that affect the gastrointestinal tract like helminths and protozoa, can lead to a range of symptoms, including unintended weight loss. 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, notes that symptoms can include “diarrhea, nausea, vomiting, and lack of appetite.” These gastrointestinal disturbances can all contribute to a reduction in food intake and nutrient absorption, resulting in unexplained weight loss. Discussing a comprehensive approach to health, including a weight loss diet for breastfeeding moms, involves ruling out various physical causes for weight changes.

If you are experiencing unexplained weight loss, especially if it is rapid or significant (5-10% of your body weight in 3-6 months), do not ignore it. While the idea of losing 10 pounds in a week without trying might sound appealing on the surface, it’s crucial to recognize that such rapid, unintended changes are often a signal from your body that something requires medical investigation. Consulting with a healthcare professional is the necessary step to identify the cause and receive appropriate care.