Few health conditions are more difficult to diagnose than headaches. Rarely is the cause as obvious as blaring music or bright lights. Many headaches seem to come and go with little to no explanation, making it tough to get to the root of the issue.

Some headache triggers are easy to miss. Because of this, tracking tools should be part of every headache treatment plan. Identifying themes in pre-headache behaviors and foods can point providers in the right direction.

What should you and your doctor be looking for? Beyond the typical causes, these nine tend to fly under the radar:

1.    Alcohol

While a glass of wine on a Saturday night might seem harmless, alcohol consumption can trigger headaches. Red wine and dark beer, in particular, contain tannins known to cause headaches. All alcoholic beverages can cause dehydration, another known cause of headaches.

The more and faster you drink, the greater your chance of a headache. Drinking on an empty stomach, or failing to alternate alcoholic and non-alcoholic drinks, can also increase your odds of getting a headache.

When in doubt, cut alcohol out. Not only might it make your headaches go away, but you’ll enjoy all sorts of other health benefits: reduced cancer risk, clearer skin, and a more functional liver, to name a few.

2.    Caffeine

Some headache medicines contain caffeine, which can augment the painkilling power of common analgesics. But caffeine, especially when consumed in large quantities, can also trigger headaches.

Some people are simply sensitive to caffeine. Others get headaches after downing a cup of coffee or tea because of what’s known as the rebound effect: Once the caffeine wears off, the pain may set in because the body has been taught to produce fewer of its own natural painkillers.

3.    Bad Posture

As incredible as your nervous system is, it can be a bit touchy. Poor posture can strain your back and neck, putting pressure on nerves in the spine. Sometimes, this nerve pain manifests as a headache.

Invest in equipment that promotes good posture. Pay attention to the position of your head and neck, particularly when using technology. Engage in exercises that strengthen your neck and back, such as superman.

4.    Poor Stress Management

The most insidious cause of headaches is stress. When you’re “on” all the time, you may suffer from hormone imbalances that cause headaches. Reducing your stress levels will not only keep headaches at bay, but also improve your quality of life.

Start by pinpointing the leading causes of stress in your life: Is your job working you into the ground? Is money on your mind all the time? Are family tensions getting under your skin?

Think in terms of short- and long-term solutions. When you can’t stop thinking about bills, clear your mind with a meditation session. Then, get to work on a budget.

5.    Strong Smells

Most people can handle noxious smells for a moment, but prolonged exposure is a recipe for a headache. Volatile organic compounds evaporate and build up in the air quickly, overwhelming the senses.

Unpleasant smells like gasoline aren’t the only culprit. Many sufferers find simply being around someone who’s wearing perfume can cause headaches. Incense and scented candles also fall into the “pleasant but potentially headache-inducing” category.

If you can’t steer clear of strong smells, try to get rid of them quickly. Turn on a fan, open a window, or put on a respirator — ideally, do all three.

What if you work in an environment, such as a factory, that requires exposure to strong smells? Take regular breaks outside. Ask your supervisor if you can change roles or work in a less smelly area.

6.    Variations in Barometric Pressure

Have you ever gotten a headache during a storm? Changes in atmospheric pressure can cause headaches as your body struggles to equalize air pressure in the inner ear.

Barometric pressure also changes with temperature. If a cold day rapidly warms up, or vice versa, don’t be surprised if you experience a headache.

7.    Skipping Meals

Think twice the next time you plan to skip lunch to get some extra work done. Hunger, or a poor diet in general, can cause your blood-glucose levels to drop. In addition to the characteristic crash in energy levels, you may experience a headache.

Keep healthy, high-calorie snacks at your desk. Bring them with you if your schedule requires you to skip a meal. A granola bar or a handful of nuts is usually enough to stave off a headache until you can eat something more substantial.

8.    Sleep Apnea

People with sleep apnea experience nighttime airway disruptions. Often caused by obesity or excessive alcohol consumption, sleep apnea prevents the brain from getting the oxygen it needs. Not only can that cause sufferers to wake up frequently during the night, but it often results in daytime headaches.

Sleep apnea should be diagnosed and treated by a physician. Some patients find relief with over-the-counter methods, like nasal strips. Others need to undergo surgery or wear a CPAP machine at night to get the rest they need.

9.    Intense Physical Activity

Exercise should be part of your daily routine. But take care not to overdo it: Too much vigorous activity could cause a headache.

Intense physical activity dilates the blood vessels in your brain, which can cause a pulsing headache in your temples. Listen to your body: If you’re pushing yourself to the point of pain, back off. Opt for less vigorous exercises, such as walking or bicycling, until you’re fit enough to push yourself further.

Although dehydration can cause headaches by itself, it’s particularly problematic when combined with overexertion. Always keep a water bottle close at hand when you exercise. Schedule a water break every ten minutes to ensure you’re staying hydrated.

If you can’t seem to get to the bottom of your headaches, share this list with your doctor. See if you can associate your episodes with any of these triggers. If you can, you’ll be that much closer to treating the cause, rather than mere symptoms, of your headaches.