Why Am I So Tired? The K Health Guide to Fatigue

By Edo Paz, MD
Medically reviewed checkmarkMedically reviewed
September 10, 2020

Are you feeling tired all the time? Are you not able to function properly due to extreme fatigue? The solutions may be relatively simple, such as making sure you get enough sleep, or making some changes to your diet. But extreme tiredness can also be a symptom of other diseases. Read on to learn about the causes of chronic fatigue, what to do to help yourself become more energetic, and when to see a doctor.

Why Am I So Tired?

You may be asking yourself, “Why am I always tired? Why can’t I seem to get out of this low-energy fog?” First of all, you’re not alone. Fatigue is a common problem and can manifest as feeling tired physically and/or mentally. The Centers for Disease Control and Prevention (CDC) reports that about 15.3% of women and 10.1% of men regularly feel very tired or exhausted.

We all know that feeling exhausted reduces our ability to work effectively, manage day-to-day routines, and maintain family and social relationships. Extreme fatigue can cause us to be more prone to irritability and mood swings. Tragically, drowsiness when driving also causes about 72,000 car crashes a year in the U.S.

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Causes of Extreme Fatigue

If you are frequently tired, the first thing to think about is your lifestyle. In particular, see if you’re:

Fatigue due to insufficient or poor quality sleep

Not surprisingly, if you are not getting a sufficient number of hours of sleep, you will feel tired. The National Heart, Lung, and Blood Institute (NHLBI) recommends that adults sleep 7-8 hours each night, yet one in three of us are not getting that. You may be able to function on more or less than the recommended number of hours, but it’s important to get in the habit of achieving them every night.

You may also feel extreme tiredness if your sleep is of poor quality. Signs that your sleep quality needs to improve are:

  • You take more than half an hour to fall asleep after getting into bed
  • You tend to wake up more than once per night
  • Once awake in the middle of the night, it takes you more than 20 minutes to get back to sleep
  • You are asleep less than 85% of your time in bed

Generally, poor sleep is due to bad sleeping habits which can be improved. There are also medical causes of poor sleep quality, such as sleep apnea.

Fatigue from stress

Stress is not a problem if it is short-lived, and it can actually help you to focus and perform better on various tasks. Problems start when your stress becomes excessive or prolonged, which can lead to physical and emotional exhaustion. Research has shown a strong correlation between insomnia and stress. When you’re stressed, you produce more stress hormones, including cortisol and adrenaline, which have various effects on your body. These hormones can give you the unpleasant feeling of being wired, despite feeling very tired.

You may be suffering from stress-related fatigue if you have some of these other symptoms:

  • Muscles that feel sore, achy, or weak
  • Headaches
  • Moodiness or irritability
  • Dizziness and blurred vision
  • Loss of appetite
  • Difficulties with short-term memory
  • Inability to concentrate or focus on tasks
  • Slowed reflexes, or difficulty making decisions
  • Feeling as if your actions are useless, or that you can’t change your situation
  • Lack of motivation
  • Feeling alone and isolated

Fatigue caused by an unhealthy diet

The old adage “you are what you eat” is really true. By eating well-balanced meals and snacks that contain enough calories and nutrients, you give yourself sufficient energy to counteract extreme tiredness. Simply eating to stave off hunger during the day is not sufficient; sugary and processed foods are counterproductive, and rob us of essential nutrients needed for energy production. Too many refined carbohydrates, such as bread, cause our blood sugar levels to spike and crash, leaving us exhausted. Make sure that your diet is made up of plenty of nutrient-rich foods such as whole grains, fresh fruit and vegetables.

Your body can function within a range of calories depending on your weight, height, age, and other factors. However, generally speaking, women should consume about 2,000 calories a day, and men 2,500 calories a day. Consuming less than 1,200 calories per day may cause your metabolism to slow down.

Conversely, if you eat too much, this can also cause fatigue. The key to healthy eating is therefore to choose certain foods that contain adequate nutrients and make sure you have meals and snacks in appropriate portions.

The impact of caffeine and energy drinks

90% of American adults drink caffeine-infused beverages almost every day. This includes coffee, tea, and energy drinks, which have high quantities of sugar in addition to containing the same amount of caffeine as a cup of coffee. Some of the smaller “energy shots” can contain up to 160mg of caffeine in a 60ml bottle. With extreme tiredness, you may start drinking too much of these drinks to give yourself a temporary energy boost.

The problem is that these caffeinated beverages have short-lived results and do not tackle your general fatigue. Caffeine has a stimulatory effect on the nervous system, and creates a momentary surge of adrenaline. However, once it subsides, you are left drained of energy; the opposite effect to what you wanted. Caffeine can also lead to other problems such as:

  • Anxiety and irritability
  • Disrupted sleep
  • Increased blood pressure

So rather than improving your fatigue, caffeine can cause you to feel worse.

Fatigue from dehydration

By the time you feel thirsty, you’ve already lost 2-3% of your body’s fluid. Even this mild dehydration can make you feel tired. This is because as you lose body fluid, your blood volume lowers, and there is less blood reaching your brain. It also means that your heart has to pump harder and use up more of your energy.

Fatigue and insufficient exercise

Being a couch potato can actually be the root cause of your tiredness and low energy. Sitting down for long periods of time can sap your energy, even if you’re watching TV, or on your computer.

Medical research has shown that exercising gives you more energy and reduces fatigue. It helps to start off gradually, so that you’re more likely to stick to an exercise routine. In fact, studies have shown that even minimal increases in physical activity, particularly for someone who has been mostly sedentary, can significantly reduce your fatigue.

Related Conditions

If you still feel tired once you have done all you can to optimize a healthy lifestyle, you may have an undiagnosed medical condition. Below are some of the most common culprits:

Chronic fatigue syndrome

Chronic fatigue syndrome (CFS), alternatively termed myalgic encephalomyelitis (ME) or systemic exertion intolerance disease (SEID), is a condition that can occur at any age, but it most commonly affects people in their 40’s and 50’s, and it’s more prevalent in women than men. Unmanaged stress is also a risk factor for CFS.

As its name suggests, the primary symptom of CFS is extreme fatigue, which can’t be explained by any other underlying medical condition. This exhaustion does not get better with rest but can get worse after any physical or mental activity. Other symptoms include:

  • Loss of memory or concentration
  • Sore throat
  • Enlarged lymph nodes in your neck or armpits
  • Unexplained muscle or joint pain
  • Headaches

Research has come up with various theories for the causes of CFS, such as a viral infection, psychological stress, or a combination of factors. Unfortunately, CFS can’t be diagnosed with a single test; rather your doctor will need to carry out many medical tests to eliminate other conditions with similar symptoms.

CFS has no cure, so treatment is focused on relieving the symptoms.


Fibromyalgia is a long-term or chronic condition that can cause you to feel pain and tenderness in different parts of your body. Fatigue is a primary symptom, as well. It affects nearly one in every 25 people and can occur at any time in someone’s life, although it commonly develops between the ages of 30-50. Women are about seven times more likely to be affected by fibromyalgia than men.

In people with fibromyalgia, there may be no physical injury or damage. Rather, the pain results from a problem in the way the nerves in the brain process pain.

Symptoms sometimes begin after a physical trauma, surgery, infection or significant psychological stress. In other cases, symptoms gradually accumulate over time with no single triggering event.

The main symptoms of fibromyalgia are:

  • Widespread pain: This is a constant dull pain for at least three months which occurs on both sides of your body and above and below your waist.
  • Fatigue: Despite sleeping a lot, tiredness can occur from first thing in the morning
  • Cognitive difficulties: A symptom commonly referred to as “fibro-fog” or “brain fog” means it is hard to focus and concentrate on mental tasks.
  • Sleep disturbance: Sleep is often disrupted by pain, and many people with fibromyalgia have other sleep disorders, such as restless legs syndrome and sleep apnea.

A practical way to differentiate fibromyalgia from CFS is that although you are fatigued with fibromyalgia, the main symptom is pain, whereas fatigue is the most prominent problem with CFS.

There is no single test for fibromyalgia, and diagnosis is accomplished by eliminating other conditions with overlapping symptoms. Despite the fact that there is no cure, a variety of medications can help control symptoms. Exercise, relaxation, and stress-reduction measures may also be beneficial.


Feeling tired and weak may be due to having this condition in which you have too few healthy red blood cells to carry enough oxygen to your body’s tissues.

There are various types of anemia including:

  • Iron deficiency anemia: This is the most common type of anemia and is due to insufficient iron in your body. Some causes of iron-deficiency anemia include insufficient consumption of iron, and bleeding (such as from heavy menstruation).
  • Vitamin deficiency anemia or pernicious anemia: Red blood cells also need folate and vitamin B-12 in order to function properly. Fortunately these are present in most foods.
  • Anemia of inflammation: Various inflammatory diseases such as cancer, HIV/AIDS, rheumatoid arthritis, kidney disease, and Crohn’s disease, can disrupt the production of red blood cells in the bone marrow.
  • Aplastic anemia: This is a rare and life-threatening condition in which your body does not produce enough red blood cells. It is caused by exposure to toxic chemicals, infections, certain medications, or autoimmune diseases.
  • Sickle cell anemia: This is a type of hemolytic anemia where red blood cells are abnormally shaped and are destroyed in the body. This causes a chronic shortage of red blood cells and is due to a defective form of hemoglobin.

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Thyroid issues

Extreme fatigue commonly occurs with thyroid disease.

The thyroid is a small, butterfly-shaped gland in the front of your neck. When it is functioning properly, it produces the right amount of thyroid hormones which keep the body’s metabolism working at a satisfactory rate. As the hormones are used, the thyroid creates replacements. However, if the thyroid malfunctions and too much or too little hormone is produced, the body uses energy faster or slower than it should.

About 20 million Americans have some form of thyroid disease. You can get it at any age, but women are affected 5-8 times more than men.


This is where you have an under-active thyroid resulting in less thyroid hormone production. The most common cause of hypothyroidism is Hashimoto’s disease, and the common symptoms of hypothyroidism include extreme tiredness or fatigue. If you are diagnosed with hypothyroidism, you will need to take thyroid hormone replacement medication.


This is where you have an overactive thyroid which produces too much thyroid hormone. The most common cause of hyperthyroidism is Graves’ disease. Treatment can include antithyroid medication, surgery to remove part of your thyroid, or other treatments.

Thyroid disease is not always easy to diagnose because the symptoms overlap with those of other conditions. However, thyroid disorder can typically be identified with blood testing, such as the thyroid stimulating hormone (TSH) test.


Fatigue is a common symptom of diabetes. According to the American Diabetes Association, 61% of people with newly diagnosed type 2 diabetes report feeling fatigued, and this was the second most-reported symptom.

In diabetes, the pancreas doesn’t produce enough insulin, or the body doesn’t use insulin effectively to absorb glucose (sugar) from the blood after you’ve eaten. This means glucose builds up in the blood rather than getting to the cells that require it to function. Treating diabetes with replacement insulin or other medications such as metformin, will act to absorb the glucose and prevent it building up to dangerous levels in the blood. However, if too much medicine is given, you can have too little glucose in your blood and become ‘hypoglycemic’ which will also cause you to feel fatigued.

Other symptoms of diabetes include:

Wanting to frequently drink or urinate, or having uncomfortable limbs, hands, and feet are likely to disrupt your sleep and consequently make you feel more fatigued.

If you do not get properly treated and your blood sugar levels remain too high, you may get complications of diabetes which will also give you fatigue.

Chronic insomnia

If lack of sleep becomes long-term, you may be suffering from chronic insomnia which affects 6-9.5% of people and can affect your quality of life in many ways in addition to feeling extreme fatigue.

Sleep apnea

Sleep apnea is where you have brief periods during sleep when you stop breathing. This means you get less oxygen and if frequent enough, this can disrupt sleep to the point of daytime exhaustion and headache. You are also likely to snore, and may wake up gasping for air. Sleep apnea can have effects on the body, such as high blood pressure.

Fatigue in Women

Women are more likely than men to report feeling tired and fatigued (43% versus 39%). This may be due to various reasons such as greater stress, less quality sleep, and being too busy to eat properly or exercise. What’s more, many conditions which have fatigue as a main symptom affect women more than men.

These conditions include:

  • Chronic fatigue syndrome
  • Fibromyalgia
  • Iron deficiency anemia
  • Thyroid disease

Despite our busy lives, it is important to put ourselves as a priority so that we can function properly and do as much as we can without being under a fog of fatigue.

Tips for Feeling Less Tired

Many of the lifestyle reasons for being always tired are interrelated and once you improve on one, you’ll find it easier to tackle other areas. For example, if you start getting sufficient quality sleep, you’ll have more energy to exercise and prepare healthy meals. Similarly, if you improve your diet, you’re more likely to have the energy to exercise and consequently get better sleep, and so on.


If you suspect your fatigue is due to poor eating habits, changing your diet may be all you need to feel energized daily. The following are some tips on improving your diet so that you are less tired:

  • Eat small frequent meals throughout the day
  • Eat snacks that are low in sugar
  • Avoid junk food and follow a well-balanced diet
  • Consume plenty of fresh fruit and vegetables
  • Drink alcoholic and caffeinated beverages in moderation, or not at all
  • Avoid caffeine in the afternoon and evening


To boost your energy levels, replace sedentary behaviors with active ones:

  • Stand rather than sit down whenever possible
  • Take the stairs instead of the elevator
  • Walk instead of driving short distances
  • Have social activities involving a physical activity such as dancing, walking, and bowling instead of sitting down watching a movie

Your increased activity will not only reduce your fatigue but give you a general sense of well-being, both physically and mentally.

Sleep patterns

Here are some tips to improve your sleep quality:

  • Turn off your electronic device and the TV at least half an hour before going to sleep—blue light from a laptop or cell-phone can make it difficult to fall asleep
  • Make sure you’re sleeping in a room that is quiet, dark and at a comfortable temperature so that you can fall asleep more easily
  • Find a sleep schedule that is good for you so that you are going to sleep before you’re overly tired but not before you’re tired. Once you have found your ideal bedtime, stick to it every night.
  • Make yourself a relaxing pre-bedtime routine, such as taking a bath or reading a book, which will prepare you to easily fall asleep
  • Limit yourself to one or two alcoholic drinks a day, and avoid drinking within three hours before bedtime
  • Avoid caffeinated drinks within 4-6 hours of bedtime


As we’ve talked about, improving your lifestyle habits can significantly reduce your fatigue but they are also great stress relievers. So make sure you get the benefits of eating a healthy diet without over- or under-eating; avoiding unhealthy habits such as smoking and drinking too much alcohol and caffeine; sleeping properly; and doing any form of exercise to give you those feel-good endorphins.

Try to find a fulfilling work-life balance so you have time to enjoy social activities, laugh, play or listen to music, be creative or volunteer for charity. Some people find meditation or yoga helpful to focus attention, instill calmness, provide physical and emotional balance, and reduce those stress triggers in your mind.

Allow yourself to say no or delegate work. It may be less stressful in the short-term to always say yes but asserting yourself will prevent more stress later.

If your self-care measures aren’t doing enough to relieve your stress, don’t be shy to seek counseling. Professional counselors or therapists can help you to identify where your stress is coming from and help you to find new coping tools.

Stay hydrated

Some useful tips for ensuring that your body gets sufficient fluids include:

  • Drink enough water consistently throughout the day so that you never feel thirsty. Here is an online calculator you can use to see how much water you need to drink each day. It is calculated based on your weight and the amount of time you exercise.
  • Drink enough water so that your urine is light yellow or clear
  • Make sure you are drinking water or non-alcoholic drinks to hydrate
  • Increase your water intake through eating more fresh fruit and vegetables

When to See a Doctor for Your Fatigue

If you’re still feeling tired all the time despite doing all you can to improve your diet, sleep and exercise habits, it’s time to see a doctor. Your doctor will talk to you about your symptoms and lifestyle and see if you have any other medical issues or are taking any medications. Your doctor may ask you to have various tests to see if you have another medical condition that is causing your extreme fatigue. If this is the case, you will get the answer to why you feel exhausted and be on your way to being treated and feeling better.

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K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Edo Paz, MD

Edo Paz is the VP of Medical at K Health. Dr. Paz has two degrees in chemistry from Harvard and earned his medical degree from Columbia University. He did his medical training in internal medicine and cardiology at New York-Presbyterian. In addition to his work at K Health, Dr. Paz is a cardiologist at White Plains Hospital, part of the Montefiore Health System. 

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