Why Am I Always Tired? Causes of Low Energy and Fatigue

Tiredness, fatigue or sleepiness: what's the difference?

People often use these words to mean the same thing, but they're a little different.

• Everyday tiredness: Feeling worn out after a long day or hard exercise, but still able to get on with life.[2][3] What usually helps: a nap or a few good nights of sleep.[2]
• Fatigue: No energy to start your usual activities, or feeling exhausted during or after them, and it doesn't get better with rest.[1] What usually helps: finding the cause, often with your GP's help.[1][2]
• Sleepiness: Struggling to stay awake or nodding off during the day.[5] What usually helps: better sleep, and a check for a sleep disorder if it keeps happening.[5]

Fatigue can come on suddenly or gradually.[1] People sometimes describe it as weakness, sleepiness or "feeling flat".[1]

What are the signs of fatigue?

Fatigue can affect your body, your thinking and your mood.[2] Signs include:

• tiredness that doesn't get better with rest[1]
• growing tired quickly after you start an activity[1]
• headaches or dizziness[2]
• sore or aching muscles, or muscle weakness[2]
• poor concentration or short-term memory problems[2]
• irritability or low motivation[2]
• slower reflexes and reactions[2]

Fatigue also affects safety. It can raise the risk of accidents at work and make driving less safe.[1]

What causes you to feel tired all the time?

Fatigue can have more than one cause working together. For many people, it comes down to a mix of lifestyle, social and emotional factors rather than an underlying medical condition.[2]

Everyday causes

• Sleep. Too little sleep, poor quality sleep and even too much sleep can cause fatigue. Noisy neighbours, young children, a snoring partner or a stuffy bedroom can get in the way.[2]
• A busy schedule. Too many commitments, such as working two jobs, can wear you down.[1][2]
• Stress and grief. Stress, grief, money worries and pressure at work can drain your energy.[1][2]
• Food and drink. A poor diet, too much caffeine and too much alcohol can leave you tired.[1] Low-kilojoule or low-carbohydrate diets may not give your body enough fuel.[2]
• Too little exercise, or too much. Regular activity improves energy and sleep for most people, but too much or the wrong kind for your body can also cause fatigue.[2]
• Shift work. Working when your body expects to be asleep confuses your body clock.[2]
• Not drinking enough. Even mild dehydration can make you feel tired.[3]

Health causes worth checking

Sometimes tiredness is a sign of a health issue. These are some of the more common ones, and the other signs that can come with them.

• Low iron: Feeling weak or listless, short of breath, dizzy, pale skin or trouble concentrating. More common in people who have periods, are pregnant or eat a vegetarian or vegan diet.[6][13]
• An underactive thyroid: Weight gain, feeling the cold, constipation, dry skin, thinning hair or muscle pain.[7]
• Sleep apnoea: Loud snoring, pauses in breathing, gasping or choking at night, or waking unrefreshed or with a headache.[5]
• Low vitamin D: Often no symptoms, but sometimes mild bone pain or muscle weakness.[8]
• An infection: A recent bout of flu, COVID-19 or glandular fever. Long COVID can cause fatigue that lasts for months.[1]
• Some medicines: Tiredness that may be a side effect of a medicine you take.[1]
• Low mood or grief: Irritability or loss of motivation.[2]

Some heart, kidney and hormone conditions, including blood sugar problems, can also cause fatigue.[1] Sometimes no cause is found at all.[1] For most people, fatigue gets better over time on its own or with simple lifestyle changes.[2]

8 habits that may help you feel less tired

These changes deal with the usual causes of tiredness. Try a few at a time and notice what makes a difference.

• Keep a regular sleep routine. Go to bed and get up at the same time each day.[3] Most adults need about 7 to 9 hours of sleep a night.[9]
• Eat regularly. Choose low GI foods, aim for at least 5 serves of vegetables and 2 of fruit a day, and include foods that contain iron.[3] Good sources of iron include red meat, chicken, fish, legumes, tofu and dark leafy greens such as spinach.[13] Foods rich in vitamin C, like citrus fruit and tomatoes, help your body absorb iron when you eat them at the same time, while tea and coffee are better between meals.[13]
• Drink enough water. As a general rule, women need about 8 cups a day and men about 10.[3] Pale yellow or straw-coloured urine is a good sign you're drinking enough. If it's darker yellow, drink more.[14]
• Move more than you sit. Regular physical activity can boost your energy and help you sleep.[2][3]
• Cut down on caffeine. Caffeine can disturb your sleep and cause energy slumps.[3]
• Go easy on alcohol. Drinking alcohol before bed affects your sleep and makes you tired the next day.[3]
• Go easy on sugary pick-me-ups. Chocolate bars and drinks high in caffeine or sugar give a short burst of energy that soon wears off.[2]
• Make time to relax. Feeling stressed uses up energy, so build relaxing activities into your day.[3]

If you've made these changes and still feel very tired, see your doctor rather than pushing through. You may have a health issue that needs checking.[1]

How energy is linked to sleep, stress and pain

Low energy is often tied up with how you're sleeping, how stressed you are and whether you're in pain.

• Too little or poor quality sleep is a common cause of fatigue.[2] See our guide on how to improve your sleep quality for habits that may help.
• Feeling stressed uses up energy,[3] and stress is one of the things that can cause fatigue.[1] For ways to bring it down, see our guide on how to manage stress.
• Pain can make sleep lighter and wake you more often,[10] and poor quality sleep can leave you tired the next day.[2] Read more about muscle and body pain.

When to see a doctor about tiredness

See your GP if you've had fatigue for more than 2 weeks and it isn't getting better.[1] See them sooner if your tiredness:

• is worrying you
• is stopping you from doing things
• comes with other symptoms, such as weight loss[1]

GPs also look out for warning signs that need checking promptly, such as:[11]

• tiredness that has come on recently in an older person who was previously well
• unexplained weight loss
• unusual bleeding
• shortness of breath
• swollen glands with no clear cause
• a fever
• new or worsening heart, gut, nerve or joint symptoms

Call triple zero (000) if you have chest pain that is severe, getting worse or has lasted longer than 10 minutes, feels heavy, crushing or tight, or comes with breathlessness, nausea, dizziness, a cold sweat, or pain in your jaw or down your left arm.[12]

What to expect at the GP

Your GP will ask about your symptoms and do a full physical examination.[1] They'll want to know:

• what your tiredness feels like and whether rest makes a difference
• how long you've felt this way and how quickly it came on
• how you're sleeping
• whether you have any other symptoms
• your diet, exercise and alcohol use
• any medicines you take[1]

It helps to jot these down before your appointment, along with anything that makes your tiredness better or worse.

If poor sleep might be part of it, a sleep diary can help you track your sleep and share it with your GP.[15] Our sleep quality guide explains what to note.

Depending on what they find, your GP may suggest blood tests or imaging.[1] Common first blood tests look at your blood count, blood sugar, thyroid, kidney and liver function, and signs of inflammation.[11] An iron study blood test is the only reliable way to check your iron levels.[6] If there are no warning signs, your GP may suggest trying lifestyle changes first and coming back in 3 to 4 weeks.[11]

From there, your GP will work with you on changes that suit you, such as the right kind of exercise, changes to diet, alcohol or smoking, psychological support or medicines if needed.[2] Check with your doctor before taking iron supplements, because too much iron can be harmful.[6]