Figuring out why you are tired often requires a little detective work, said Shannon Sullivan, a sleep medicine specialist at Stanford University.

On the one hand, your sleep routine might just need a few tweaks. But certain health conditions or medications could also be to blame.

The good news, Sullivan said, is there are ways to identify and treat the source of your fatigue, which can often help you to feel better.

“It’s a part of medicine with a great deal of hope,” she said.

The first thing you should do is review your sleep habits, Sullivan said. Have you recently strayed from your normal sleep schedule? Have you been stressed?

If not, your sleep routine might need some sprucing up. Make sure you are getting at least seven hours of sleep every night (some people need more) and try to go to bed and wake up at the same times every day. Much like a toddler’s naps, your own sleep will be better when it is consistent, Sullivan said.

If you have a regular afternoon coffee or an evening glass of wine, try skipping it. And avoid scrolling on your phone or snacking just before bed. All of these activities can lower the quality of your sleep. The timing of your meals can make a difference, too; aim to finish dinner at least two to three hours before bedtime.

In any case, it is always a good idea to visit a doctor if you are struggling with sleep, said Kara Dupuy-McCauley, a pulmonologist and sleep medicine specialist at the Mayo Clinic. A sleep specialist can help improve your sleep habits. He or she will also ask about your symptoms, medical records and family health history to understand if anything else might be zapping your energy.

Sleep disorders are common, Dupuy-McCauley said. They can make you feel like you might doze off during the day, so if you struggle with daytime sleepiness, a doctor will likely consider the following.

Insomnia. Roughly 30 per cent of adults worldwide have trouble falling or staying asleep or both, which can leave them feeling unrest...