Heightened sensitivity to smells is common and can have several possible causes. It can be temporary and benign, but sometimes it signals an underlying medical or psychological issue.
What smell sensitivity is
Being “so sensitive to smells” is often described as hyperosmia, meaning odors feel unusually strong, irritating, or even nauseating compared to what others report. People with this sensitivity may react strongly to perfumes, cleaning products, smoke, food smells, or chemical odors and can develop headaches, nausea, or a feeling of sensory overload in response.
Common physical and hormonal causes
Several body-related factors can increase smell sensitivity:
- Hormonal shifts (such as during pregnancy, parts of the menstrual cycle, puberty, or menopause) can temporarily enhance the sense of smell by changing how the brain processes odors.
- Migraines, certain infections, allergies, sinus issues, or autoimmune and neurological conditions can all affect the olfactory system and make smells seem more intense or unpleasant.
- Some medications, vitamin B12 deficiency, and conditions like diabetes or thyroid disorders have also been linked to changes in smell, including increased sensitivity in some people.
Role of stress, anxiety, and the brain
Stress and anxiety can “turn up the volume” on all senses, including smell. When the body is in a fight‑or‑flight state, the nervous system becomes more alert, and odors that were easy to ignore can feel overpowering.
People who are anxious or under chronic stress may pay more attention to smells, interpret them as threatening or disgusting, and then experience a reinforcing loop where the smells feel even stronger and more distressing.
Environmental and neurodivergent factors
Living or working around strong odors, air pollution, or many fragranced products can make the nose more reactive over time, so even everyday smells feel like “too much.”
Some neurodivergent people (for example, autistic or highly sensory‑sensitive individuals) report “olfactory overload,” where normal environments feel overwhelming because the brain processes sensory input, including smell, more intensely.
When to seek help and what to do
It is important to see a healthcare professional if:
- Your smell sensitivity is new, worsening, linked to migraines, neurological symptoms, or major life changes.
- It interferes with eating, sleep, work, or going out in public.
A doctor can look for physical causes (hormones, deficiencies, medications, sinus or neurological issues), and a mental health professional can help if anxiety or sensory overload plays a big role.
In the meantime, practical steps include reducing exposure to triggers (unscented products, better ventilation), managing stress and sleep, and keeping a brief “smell diary” to track patterns that you can bring to an appointment.
