Figuring out why you’re tired often requires a little detective work, said Dr Shannon Sullivan, a sleep medicine specialist at Stanford University in the US.

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, Dr Sullivan said, is there are ways to identify and treat the source of your fatigue, which can often help you feel better. “It’s a part of medicine with a great deal of hope,” she said.

Are you really getting enough sleep?

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

If not, your sleep routine might need some sprucing. Make sure you’re 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’s consistent, Dr 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’s always a good idea to visit a doctor if you’re struggling with sleep, said Dr Kara Dupuy-McCauley, a pulmonologist and sleep medicine specialist at the Mayo Clinic in Rochester, US. A sleep specialist can help improve your sleep habits. They’ll also ask about your symptoms, medical records and family health history to understand if anything else might be zapping your energy.

Could you have a sleep disorder?

Sleep disorders are common, Dr 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 things.

First, insomnia. Roughly 30 per cent of adults worldwide have trouble falling or staying asleep (or both), which can leave them feeling unrested and unable to focus. Insomnia can be a short-term problem caused by stress or jet lag. But if symptoms occur at least three times a week for three months or more, you could have chronic insomnia.

How it’s treated will depend on its cause, but in many cases, cognitive behavioural therapy is more effective than medication.

Another common sleep disorder is obstructive sleep apnoea, which occurs when the throat muscles collapse while sleeping, blocking airflow and causing you to periodically stop breathing. Some people may have no symptoms, while others might snore, wake up gasping for air or feel sleepy during the day. Untreated, serious cases can lead to heart disease, stroke and diabetes. Your doctor can diagnose the condition with an at-home wearable device and treatment with a CPAP machine is often effective.

Restless leg syndrome is characterised by an uncomfortable feeling in the legs and an urge to move them. Symptoms tend to be worse at night and can start after you settle down to rest, making it hard to fall asleep. Massaging your legs and cutting back or avoiding alcohol and caffeine can help reduce symptoms, Dr Dupuy-McCauley said. Treating iron deficiency can also help, she added.

What else can cause fatigue?

Keep in mind that your tiredness, weariness or low energy could be caused by any other number of things, Dr Sullivan said. So it’s important to rule out all the major contenders. Here are some that a doctor might consider.

A common hormonal issue associated with fatigue is hypothyroidism, which occurs when the thyroid gland doesn’t make enough thyroid hormone, said Dr Susan Samson, an endocrinologist at the Mayo Clinic. The good news is that it’s easy to test for and treat, Dr Samson said — though you may have to ask for testing during your regular blood work.

Iron deficiency, which is more likely if you’re menstruating or on a vegetarian or vegan diet, can cause fatigue; as can low levels of both Vitamin D and Vitamin B12. Blood tests can reveal if you are deficient in any of these and supplements can help, Dr Dupuy-McCauley said.

Many other medical conditions, such as diabetes, depression, gastrointestinal conditions and long Covid feature fatigue as a hallmark symptom. Chronic fatigue syndrome (also known as myalgic encephalomyelitis, or ME/CFS) causes debilitating fatigue and has no cure, though its symptoms can be managed.

Apart from diseases, a long list of drugs including antidepressants, benzodiazepines and antihistamines can also make you feel tired.

All of this might be exhausting just to contemplate. But experts agree that it’s usually within reach to determine why someone is tired. “It’s always a good idea to just go to the sleep doctor,” Dr Dupuy-McCauley said.

NYTNS