For most people, overpowering or intense odors may just be a mild annoyance, but strong smells are prime triggers for those with migraines. Multiple studies have found that up to 95% of individuals with migraines also have osmophobia, a distinct sensitivity to specific smells, a condition that triggers or worsens migraine flare-ups when such individuals are exposed to certain odors. Keeping that in mind, here are some common smells that trigger migraine episodes in people:

Cleaning products
Cleaning products such as bleach and disinfectants have strong antibacterial and deodorizing properties. These properties give such products a strong, instantly identifiable smell that can be sensed from several meters away. The frequent use of bleach to clean homes, offices, auditoriums, and party spaces means its overpowering smell has become commonplace. Unfortunately, these powerful fumes are a prime trigger for migraine attacks in vulnerable people. It is not uncommon for someone with a migraine to feel a strong headache building up as soon as they breathe in the smell of cleaning products around them.
In this way, the deodorizing elements in cleaning products ironically make them hazardous to migraine sufferers.

Scented candles
Scented candles contain several components and elements that trigger migraines. For example, heated sage or jasmine oils are among the chemicals that release irritants that cause sinus inflammation and nose and throat issues. These irritants also react with an individual’s skin to cause allergic reactions, leading to headaches. Not all scented candles are harmful to use, though. Certain flavors, such as freshly picked eucalyptus leaves, lavender, and vanilla, are some scents less likely to cause a migraine flare-up.
Nevertheless, for people with migraines, using unscented candles or incense sticks is the safest bet to keep their flare-ups at bay.

Car exhaust
The fumes emanating from the exhaust pipes of vehicles are some of the worst environmental pollutants. These elements contain hazardous chemicals such as carbon monoxide, a toxin that can cause health issues to those overexposed to it. Exhaust fumes and gas leaks from vehicle exhausts also have a strong odor. Due to that, people with migraines will likely experience shortness of breath, headaches, nausea, dizziness, and fatigue if exposed to vehicle exhaust fumes too often.

Strong perfumes
Strong perfume odors are arguably the most common smells that trigger migraine attacks in people. It happens because perfumes contain many ingredients that can irritate a person’s nasal passages and trigger headaches. People with migraines who nonetheless love using perfumes can try skipping the brands that use synthetic substances like vanillin in their perfumes. Vanillin is an element that mimics the natural scent of vanilla. Ironically, vanilla is a substance that soothes headaches, while its synthetic counterpart, vanillin, worsens them.
Instead of avoiding perfumes entirely, people with migraines can use natural, organic perfumes instead of those loaded with synthetic ingredients. As the example above shows, many natural perfumes are less likely to trigger migraine headaches than synthetic ones.

Some other smells that trigger migraines come from oil paints, paint thinners, and burning gasoline. One must refrain from using such products to avoid recurrent migraine episodes.