Most people wouldn’t consider daytime sleepiness to be a big deal. A lot of the time, it isn’t. But if your sleepiness is ongoing and getting in the way of your everyday life, it may be time to see the doctor.

Many factors can be contributing to your sleepiness. It’s possible you’re not getting enough sleep because of an underlying health issue, like sleep apnea or narcolepsy. Your doctor can help you figure out the cause of your tiredness and how to manage it.

Here are 12 possible reasons why you may feel tired all the time.

If you have a tendency to skip meals, you may not be getting the calories you need to keep your energy up. Long gaps in between meals can cause your blood sugar to drop, decreasing your energy.

It’s important not to skip meals. In fact, you should also eat healthy energy-boosting snacks between meals, especially when you start to feel sluggish. Healthy snack options include bananas, peanut butter, whole-grain crackers, protein bars, dried fruit, and nuts.

Being tired all the time can also be a sign of vitamin deficiency. This could include low levels of vitamin D, vitamin B-12, iron, magnesium, or potassium. A routine blood test can help identify a deficiency.

Your doctor may recommend taking supplements. You can also increase your intake of certain foods to correct a deficiency naturally. For example, eating clams, beef, and liver may reverse a B-12 deficiency.

Late nights can take a toll on your energy level. Most adults need between seven and nine hours of sleep each night. If you get into a habit of staying up late, you’re putting yourself at risk for sleep deprivation.

Practice better sleep habits to boost your energy. Go to bed earlier and take steps to improve the quality of your sleep. Sleep in a dark, quiet, and comfortable room. Avoid stimulating activities before bed, like exercise and watching TV.

If your sleep doesn’t improve with self-care, talk to your doctor. You may need a prescription sleep aid or a sleep study.

Being overweight can also cause tiredness. The more weight you carry, the harder your body must work to complete everyday tasks like climbing stairs or cleaning.

Come up with a plan to lose weight and improve your energy level. Start with light activity such as walking or swimming, and gradually increase intensity as your stamina allows. Also, eat more fresh fruits, vegetables, and whole grains. Curb your intake of sugar, junk foods, and fatty foods.

Physical activity can also boost your energy level. A sedentary lifestyle, on the other hand, can leave you feeling exhausted and sleepy.

In one study, researchers investigated how an inactive and sedentary lifestyle influenced feelings of fatigue in women. Seventy-three women were included in the study. Some of the women’s lifestyles met physical activity recommendations, while others weren’t physically active.

According to the findings, the less sedentary women had a significantly lower level of fatigue. This supports the notion that increased physical activity contributes to more energy and vigor.

Chronic stress can cause headaches, muscle tension, stomach problems, and fatigue.

When under stress, your body goes into fight-or-flight mode. This causes an increase in cortisol and adrenaline, which prepares your body to deal with such situations. In small doses, this response is safe. In the case of chronic or ongoing stress, it takes a toll on your body’s resources, leaving you feeling exhausted.

Learning how to control stress may improve your energy level. Start by setting limitations, creating realistic goals, and practicing changes to your thought patterns. Deep breathing and meditation can also help you stay calm in stressful situations.

When you feel depressed, lack of energy and tiredness can follow. If you’re experiencing depression, talk to your doctor and discuss treatment options.

Your doctor may prescribe an antidepressant or an anti-anxiety medication. You might also benefit from mental health counseling. Cognitive behavioral therapy is a type of treatment that helps correct negative thought patterns that lead to a negative mood and depression.

A sleep disorder is sometimes the underlying cause of tiredness. If your energy level doesn’t improve after a few weeks, or after you make the right lifestyle modifications, speak with your doctor. You may need to see a sleep specialist.

A sleep disorder like sleep apnea can be causing your tiredness. Sleep apnea is when your breathing pauses while you’re asleep. As a result, your brain and body don’t receive enough oxygen at night. This can lead to daytime fatigue.

Sleep apnea is a serious condition. It can cause high blood pressure, poor concentration, and lead to a stroke or heart attack. Treatment involves using a CPAP machine or an oral device to keep the upper airway open while you’re asleep.

You may feel tired all the time if you have chronic fatigue syndrome. This condition causes extreme fatigue that doesn’t improve with sleep. Its cause is unknown.

There’s no test to confirm chronic fatigue. Your doctor must rule out other health problems before making a diagnosis. Treatment involves learning how to live within your physical limitations or pacing yourself. Moderate exercise may also help you feel better and increase your energy.

Fibromyalgia causes widespread muscle pain and tenderness. This condition affects the muscles and soft tissue, but it can also cause fatigue. Because of the pain, some people with the condition are unable to sleep at night. This can lead to daytime sleepiness and fatigue.

Taking an over-the-counter pain reliever can help improve pain and sleep. Also, some people have had positive results with an antidepressant, as well as physical therapy and exercise.

Sometimes, medication can cause you to feel tired all the time. Think back to when you first noticed daytime sleepiness. Was this around the time when you started a new medication?

Check drug labels to see if fatigue is a common side effect. If so, talk to your doctor. They might be able to prescribe another drug, or reduce your dosage.

Feeling tired all the time can also be a symptom of diabetes. When you have diabetes, your body doesn’t make enough insulin. This can cause high blood sugar, which can affect your concentration and leave you feeling fatigued and irritable.

See a doctor for any unexplained fatigue that doesn’t improve. Keep in mind that fatigue can also be a symptom of other medical conditions like heart disease and cancer.

Some days are more tiring than others. It’s important to recognize ordinary sleepiness from excessive tiredness.

In most cases, excessive sleepiness can be fixed with some lifestyle changes. If you still feel worn out after trying to manage your fatigue on your own, talk to your doctor. You may have a sleep disorder or another medical condition that needs attention.