If you can smell yourself, it usually means your body odor has changed or intensified enough to override your brain’s built-in filtering system. Under normal circumstances, your nose tunes out your own scent within minutes of exposure. So when you do notice it, something has shifted, whether that’s hormonal, dietary, hygiene-related, or occasionally medical.
The good news: most causes are harmless and fixable. But in some cases, a new or persistent smell can signal a health issue worth investigating.
Why You Normally Can’t Smell Yourself
Your brain is constantly filtering out background sensory information so you can focus on what’s new or potentially dangerous. This process, called olfactory adaptation, happens at two levels: in the smell receptors inside your nose and in the brain regions that process scent. After prolonged or repeated exposure to any odor, your perception of it fades. This is why you stop noticing your own perfume after 20 minutes or can’t tell your house has a smell until you leave and come back.
Your own body scent is the ultimate constant exposure. You’ve been marinating in it your entire life, so your brain files it under “neutral, ignore.” When that scent suddenly registers, it means either the smell itself has changed enough to feel unfamiliar to your brain, or it’s become strong enough to overwhelm the adaptation process.
Common Reasons Your Body Odor Changed
Hormonal Shifts
Apocrine sweat glands, the ones concentrated in your armpits and groin, produce a thick, protein-and-fat-rich sweat that bacteria love to feed on. These glands don’t fully activate until puberty, which is why teenagers suddenly develop body odor. But hormonal changes throughout life can ramp them up again. Pregnancy, menopause, and thyroid conditions all increase sweating and alter sweat composition, creating unfamiliar odors your nose hasn’t adapted to.
Stress sweat is also different from exercise sweat. When you’re anxious or stressed, your apocrine glands fire (not the watery eccrine glands that cool you down), producing sweat that smells stronger because of its higher protein content.
Diet
Certain foods produce volatile sulfur compounds that your body excretes through your skin, breath, and urine for hours after eating. Garlic is a well-studied example. When you digest it, your body produces a compound called allyl methyl sulfide, which has an extremely low odor threshold (detectable at just 0.14 parts per billion). This compound travels through your bloodstream, passes through the network of capillaries just beneath your skin, and escapes with perspiration. Onions, cruciferous vegetables like broccoli and cabbage, and heavy spice use can produce similar effects.
Alcohol and caffeine also affect body odor indirectly by increasing sweating and altering the chemical environment on your skin.
Medications
Several classes of prescription drugs are linked to changes in how you smell, both your body odor and your perception of odors. Antidepressants, cholesterol-lowering drugs, diabetes medications, proton pump inhibitors (used for acid reflux), and anticonvulsants have all been associated with phantom odor perception, where you smell something that others don’t. In adults over 60, diabetes medications and cholesterol drugs were associated with 74 to 88 percent greater odds of reporting phantom smells. If a new medication lines up with when you started noticing yourself, that connection is worth mentioning to your doctor.
When a Smell Points to a Health Issue
Certain medical conditions produce distinctive odors that are strong enough to break through your olfactory adaptation. These tend to be more specific than “I smell like B.O.” and often come with other symptoms.
Fruity or nail-polish-remover smell: When blood sugar is dangerously high and your body can’t use glucose for energy, it breaks down fat instead, producing chemicals called ketones. One of these, acetone, causes a characteristic sweet or fruity odor on the breath. This is a hallmark of diabetic ketoacidosis, a serious complication of diabetes that needs immediate attention. It typically comes with extreme thirst, frequent urination, nausea, and confusion.
Ammonia or bleach-like smell: When the kidneys aren’t filtering waste properly, urea builds up in the blood and can be excreted through sweat and breath. In severe, untreated kidney disease, the breath can smell like urine. This is usually accompanied by fatigue, swelling, and changes in urination.
Sweet, musty smell: Severe liver disease can cause a distinct musty sweetness on the breath and in urine, produced by sulfur-containing compounds that accumulate when the liver can’t process amino acids normally.
Persistent fishy odor: A rare genetic condition called trimethylaminuria prevents your body from breaking down a compound found in foods like eggs, fish, and beans. People with this condition excrete the unprocessed compound through sweat, breath, and urine, producing a strong smell resembling rotting fish. It’s inherited, present from birth in many cases, and diagnosed through a urine test that measures the ratio of specific compounds.
Smell Distortions That Mimic Body Odor
Sometimes the problem isn’t your body at all. It’s your nose. Two conditions can make you perceive smells that aren’t there or warp how real smells register.
Phantosmia is the perception of a smell with no external source. You might smell something foul and assume it’s you, but nobody else can detect it. Causes range from sinus infections and head injuries to neurological conditions. Since the COVID-19 pandemic, cases of phantosmia have surged, often developing as people recover from post-infection loss of smell. Research has linked this to structural changes in the brain’s smell-processing areas and shrinkage of the olfactory bulb after infection.
Parosmia distorts real smells, making familiar scents register as unpleasant or rotten. This has also increased dramatically post-COVID. If you notice that everything, including your own skin, smells “off” in a way that’s hard to describe, parosmia is a likely explanation.
Olfactory Reference Syndrome
Some people become intensely preoccupied with the belief that they emit an offensive odor, even though others can’t detect anything. This condition, called olfactory reference syndrome, is a recognized psychiatric condition distinct from simply being self-conscious. The core feature is persistent, distressing conviction about a body odor that no one else perceives. It often leads to social withdrawal, excessive hygiene rituals, and repeated reassurance-seeking. If your concern about smelling yourself is causing significant anxiety and the people around you consistently say they don’t notice anything, this is worth exploring with a mental health professional.
What to Do About It
Start with the simplest explanations. Think about what changed recently: new medications, dietary shifts, increased stress, hormonal transitions like perimenopause. Wearing breathable fabrics, using antibacterial soap on odor-prone areas, and staying hydrated all reduce the bacterial activity that converts sweat into smell.
If the odor is new, persistent, and doesn’t respond to hygiene changes, or if it has a distinctive quality (fruity, ammonia-like, fishy, musty), a basic medical workup can rule out metabolic causes. This typically involves blood work and a urine test to check for diabetes, thyroid dysfunction, kidney function, and liver function. These are routine, inexpensive tests that can either identify a treatable cause or give you peace of mind.
If you recovered from COVID in the past two years and smells seem distorted or you’re perceiving odors that aren’t there, smell retraining therapy (deliberately sniffing specific scents daily) has shown benefit for many people with post-viral smell disorders, though recovery can take months.