The first step to improving low energy is to find out what’s causing it. Diet, medications, problems with your sleep environment, allergies and other health conditions are just a few of the things that could be making you fatigued, according to Elizabeth Bradley, M.D., the medical director for the Center of Functional Medicine at the Cleveland Clinic in Ohio. Some of these issues can be addressed with minor lifestyle changes. Others, though, may require the guidance of a healthcare professional. Let’s take a closer look at what could be causing you to feel tired.

1. It could be your diet

Food is fuel, and what you eat (or don’t) can determine how much energy you have that day—and in the long run as well. These are a few ways to make sure you’re fueling up right.

Limit trips to the drive-through

Most fast foods are known energy killers because of their high-fat and low-fiber content, which slows your digestion way down and limits energy-boosting nutrients. Large-scale studies also show that diets high in saturated fat are associated with diabetes, constipation and other health issues that can dramatically affect your energy.

Know how your body handles caffeine

Can’t live without your morning cup of joe? “Caffeine drives cortisol,” a hormone that triggers the fight-or-flight response, says Dr. Bradley. “Cortisol gives you energy and you feel great, but then you feel that lull.” Although it is generally considered safe for adults to consume up to 400 mg of caffeine a day (or about four to five cups of coffee), caffeine affects people in different ways, so it’s important to learn how your body reacts to the amount you consume and when. For some people, says Dr. Bradley, even one early-morning shot of espresso can disturb your nightly zzz’s, leaving you lethargic the next day.

Be strategic about bedtime snacks

Having said that food is fuel, it’s also not what your body needs immediately before bedtime, especially if you have GERD, a condition where stomach acid splashes back into your throat, causing heartburn, says Dr. Bradley. Then again, going to bed hungry can also disrupt your sleep. “You need to eat enough calories during the day to stay satiated through the evening,” she says. If you must have a late-night snack, choose nutrient-rich carbs, like an apple paired with almond butter or high-fiber, gluten-free crackers that will satisfy cravings without causing a spike in blood sugar that will keep you from falling asleep.

Beware the effects of alcohol

That nightcap might help you fall asleep fast, but the sedative nature of alcohol is temporary and diminishes the quality of your sleep. Studies show that as the body processes alcohol, it stimulates part of the brain that may cause you to awaken throughout the night and interferes with the cycles of REM and non-REM sleep that you need to feel refreshed in the morning.

Look out for food allergies

Your body’s inability to properly process certain foods can cause an imbalance in nutrients that leads to fatigue. If you suspect that could be an issue, Dr. Bradley recommends an “elimination diet,” which involves removing specific foods from your meals to see if your energy improves. Elimination diets can sometimes help identify such conditions as lactose intolerance or celiac disease.

Avoid sugar

For sustained energy throughout the day, “limit your simple carbs and sugar,” says Dr. Bradley. Many people fall into an energy-depleting cycle when their diet includes too many processed grains, such as white bread and pasta, and foods high in added sugar. These foods spike your blood sugar level at first, leading to an energy plummet later. Moreover, research suggests they cause addictive-like cravings for more sugary foods. “With a diet that’s high in sugar, you feel the highs and lows of energy—it can be a vicious cycle,” says Dr. Bradley. Instead, a diet that focuses on healthy fats and protein, such as the keto diet, may eventually improve your energy levels. And choose sugar free desserts when you need a sweet pick-me-up.

2. It could be your menstrual cycle

Nearly nine out of every 10 women say they experience one or more symptoms of premenstrual syndrome (PMS), including headaches, feeling tired, sleeping problems and depression. Doctors are still looking into what causes these PMS effects, and why some women experience them more than others, but fluctuating hormone levels throughout your menstrual cycle are thought to play a key role. A more severe form of PMS known as premenstrual dysphoric disorder (PMDD) can cause some women to experience extreme fatigue and difficulty with concentration. This is especially true for women with a personal or family history of depression or other mood disorders. And finally, heavy bleeding can cause iron depletion, which may also lead to fatigue during your menstrual cycle. “If you’re having really heavy clots or menses, I’d recommend an iron supplement,” says Dr. Bradley.

3. It could be your medications

Drowsiness is one of the most commonly reported side effects of many over-the-counter and prescription medications, including:

antihistaminesantiemeticsantipsychoticsanticonvulsantsanxiety and depression medicationsblood pressure medicationsmuscle relaxantsopioids and other pain medications

The reason? These meds are believed to disrupt neurotransmitters in your brain that help regulate alertness and sleepiness. What’s more, “ibuprofen and certain antibiotics can make you feel fatigued because they affect your gut microbiome, and that can affect what nutrients you’re absorbing,” adds Dr. Bradley. Some hormonal birth control methods, including certain pills, transdermal patches and intrauterine devices or implants, can also induce daytime fatigue, according to studies. (So much so, in fact, that they’ve been explored as potential treatments for insomnia in young women.) Talk with your doctor about switching meds or adjusting doses if you think your birth control is causing drowsiness.

4. It could be allergies

Many people who experience allergy flare-ups describe “brain fog,” a sensation of haziness, tiredness and difficulty with concentrating. “Allergies activate the immune system, and that alone can make you feel fatigued,” says Dr. Bradley. It can also be challenging to get a good night’s sleep due to pesky symptoms like congestion, sneezing and itchy eyes. Unfortunately, allergy medicines—even the newer generation antihistamines—can further contribute to drowsiness. Antihistamines are designed to bind to something called H1 receptors in your body, which then prevent an allergic reaction from taking place. But some of the first-generation antihistamines also cross the blood-brain barrier, attaching to neurotransmitters in the brain that induces sleepiness. The newer antihistamines on the market do a better job at avoiding drowsiness, but since reactions to these medicines can vary widely from person to person, work with your doctor to find one that’s best for you.

5. It could be your mental health

Your energy level is affected by sleep, and sleep can be heavily impacted by your mood. Never underestimate the physical impact of stress, anxiety and depression on the body—“stress is the number one reason we’re not sleeping,” says Dr. Bradley. Here’s what happens: When your brain perceives a stressful event, it releases the hormone cortisol into the body to make you feel more alert. Although that rush of cortisol can be life-saving (You outran the bear! You aced your job interview!), it’s devastating to the quality of your sleep. Stress, depression and tiredness are all closely linked, and because there is much overlap in the symptoms of depression and fatigue, including difficulty concentrating and feeling disinterested, it can be difficult to determine which condition to tackle first. That’s why it’s important to speak with your doctor about your mental health. The good news: Along with treating any underlying mental health conditions, managing chronic stress can help you get the restful sleep you need. Try these mind-calming techniques:

Listen to a sleep podcast. Drift off to whimsical or soothing bedtime stories, ambient nature sounds or ASMR (autonomous sensory meridian response).Stretch with purpose. Simple, low-impact yoga poses can release tension throughout your body and signal to your brain it’s time to rest.Practice mindfulness or sleep meditation, which often involves focused, pattern-based breathing. Need help getting started? Try a meditation app.

6. It could be your sleep environment

The quality of your sleep plays a big role in determining your daytime energy. Help your body achieve more restorative shut-eye by ensuring your bedroom is cool, dark and free of distractions. Look around the room—there are probably more sleep enemies in there than you realize. Take these steps to create a better nighttime environment.

Control the sound

Sleeping in pin-drop silence doesn’t work for everyone, but it’s important to reduce the sharp noises that can startle you awake, such as a neighbor yelling or a car honking. If you or your partner snores, speak with a sleep specialist or look into natural ways to stop snoring. To help drown out other sounds, a fan or white noise machine can help by creating a consistent, low ambient sound that often lulls people to sleep.

Power down

Did you know that the blue light emitted from your mobile phone, television or computer keeps your brain alert? Experts recommend that you power down devices at least 60 minutes before bedtime. But if you’re caught in a “just-one-more” binge on Netflix or must scroll your newsfeeds before bed, try using a pair of blue light filtering glasses. Once the lights are out, defend against streetlights or your partner’s reading lamp by using a sleep mask, blackout shades or light-filtering curtains.

Check the temp

Experts say the best temperature for falling asleep is between 60 °F and 67 °F. To stay cool throughout the night, opt for breathable blankets and comforters that do not retain heat, such as those made of cotton, wool or bamboo fabric.

7. It could be too much sleep

So how much sleep do you need to get your energy back? Around eight hours is the magic number for most adults, according to the National Sleep Foundation. While you’re probably familiar with the consequences of skimping on zzz’s, the effects of oversleeping are less-known but equally severe. Although researchers do not understand the exact reason, oversleeping is related to many health issues, including diabetes,obesity, heart disease,depression and mood disorders and headaches, all of which can make you more tired. Occasional oversleeping may simply be caused by poor sleep quality, but regularly overdoing it could also be a sign of something serious, like hypersomnia, a clinical condition of excessive sleepiness that can impair daytime functioning, alertness and quality of life. If oversleeping becomes your norm, speak with your doctor.

8. It could be too much sun

If you’ve ever felt completely zonked after a day at the beach, there’s a reason for that. Long periods of sun exposure can physically exhaust your body as it works harder to regulate its internal temperature, manage fluid and electrolyte loss and cope with chemical changes due to UV light. If you’re planning to be outside for a long period, reduce your risk of heat exhaustion by taking frequent breaks in activity, resting in shade and drinking water. And don’t forget your sunscreen—no one can sleep comfortably with a scorching sunburn!

9. It could be another health condition

If you continue to experience chronic fatigue after making lifestyle adjustments, it is important to speak with a doctor. Sometimes feeling tired can be a sign of an underlying medical condition, including:

anemia or other vitamin deficienciesautoimmune disorders such as lupus or rheumatoid arthritiscancerheart diseasehemochromatosis, a condition in which your body absorbs more iron than it useshormonal disorders or imbalances, such as hypothyroidisminfection, such as mononucleosis or HIVkidney diseaselung problems, such as COPD or emphysemaother chronic conditions, such as fibromyalgia or myalgic encephalomyelitis

10 ways to feel less tired

There is no one-size-fits-all approach to boosting your daytime energy—shaking those feelings of tiredness for good is all about finding what works for you. Little changes can add up to big results, so try a few of these tips and see if you notice a difference. Need more help turning your bedroom into a sleep sanctuary? Check out these 10 sleep products designed to help you drift off to dreamland.

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