Why Am I Always Tired? Common Causes and What to Do Next

Constant tiredness isn't normal. If you're perpetually exhausted despite reasonable sleep, something is asking for attention. The causes range from straightforward lifestyle factors to underlying health conditions—and understanding the possibilities helps you take appropriate action.

Here's what might be happening and what to do about it.

First, Define the Problem

"Tired" means different things to different people. Getting specific helps identify causes.

Are you sleepy during the day despite sleeping at night? That suggests sleep quality issues. Do you have energy to start but crash partway through the day? Possible blood sugar or nutrition factors. Feel too exhausted to do things you normally enjoy? Could indicate mood-related causes.

The pattern matters. When did it start? Is it constant or variable? What makes it better or worse?

Sleep Issues: The Obvious Starting Point

Most persistent fatigue traces to sleep problems—even when people believe they're sleeping adequately.

Sleep quantity. Adults need 7-9 hours. Many people chronically undersleep and normalise the resulting fatigue. Sleep quality. You might be in bed for eight hours but not getting quality rest. Sleep apnoea, periodic limb movements, and other sleep disorders fragment sleep without you realising. Sleep timing. Irregular schedules disrupt circadian rhythms. Shift workers and people with inconsistent bedtimes often experience chronic fatigue despite adequate total sleep time. Sleep environment. Temperature, light, noise, and device use before bed all affect sleep quality.

If you haven't examined your sleep habits closely, start here. Track your sleep with a wearable or app. Notice patterns. Many people discover obvious opportunities for improvement.

Lifestyle Factors That Drain Energy

Beyond sleep, several lifestyle elements affect energy levels.

Dehydration. Even mild dehydration causes fatigue. Most people don't drink enough water, especially when busy or stressed. Nutrition. What you eat affects energy. Processed foods, excessive sugar, and inadequate protein can all contribute to tiredness. So can simply not eating enough. Physical activity. Counterintuitively, being sedentary makes you more tired. Regular exercise improves energy levels and sleep quality. Too little movement breeds fatigue. Caffeine. While providing short-term alertness, caffeine consumed after early afternoon can disrupt sleep quality, creating a cycle of tiredness and more caffeine. Alcohol. Even moderate alcohol consumption reduces sleep quality and can cause next-day fatigue.

Medical Conditions Worth Considering

When lifestyle factors don't explain persistent tiredness, underlying conditions deserve consideration.

Anaemia. Low iron or other nutrient deficiencies affecting red blood cells cause fatigue. This is particularly common in women, vegetarians, and people with certain digestive conditions. Thyroid disorders. An underactive thyroid (hypothyroidism) commonly causes fatigue, along with weight gain, cold sensitivity, and other symptoms. Diabetes and blood sugar issues. Undiagnosed diabetes or prediabetic states can cause significant fatigue, particularly after meals. Infections. Chronic viral infections, including post-viral syndromes, can cause prolonged fatigue. This has become more recognised since the pandemic. Heart and lung conditions. When organs aren't working efficiently, the body compensates in ways that cause tiredness. Autoimmune conditions. Conditions where the immune system is chronically activated often present with fatigue.

These aren't diagnoses to make yourself—they're possibilities to discuss with a physician if lifestyle factors don't explain your tiredness.

Mental Health and Fatigue

The connection between mental health and energy is profound.

Depression. Fatigue is a core symptom of depression, often appearing before or alongside mood changes. Anxiety. Chronic anxiety is exhausting. The body in constant alert mode drains energy. Stress. Prolonged stress elevates cortisol, which disrupts sleep and depletes energy reserves. Burnout. Extended overwork without recovery leads to a state of physical and emotional exhaustion.

Mental health factors don't make fatigue less real. They're legitimate causes requiring attention.

When to See a Doctor

Seek medical evaluation for fatigue that:

• Persists for more than two weeks without clear explanation

• Is severe enough to significantly impact daily functioning

• Accompanies other symptoms like unexplained weight change, fever, pain, or cognitive difficulties

• Doesn't improve with sleep and lifestyle adjustments

Doctors can order appropriate tests—blood work for anaemia, thyroid function, vitamin levels, blood sugar, and other relevant markers. Some causes have simple treatments once identified.

Steps to Take Now

Track your symptoms. Note energy levels throughout the day, sleep quality, food intake, and other patterns. Information helps both self-understanding and medical consultations. Optimise the basics. Before pursuing complex explanations, ensure sleep, hydration, nutrition, and exercise are genuinely adequate. Small improvements here often yield significant results. Consider context. Has anything changed recently? New stress, medication, schedule change? Sometimes the cause is obvious once you look. Consult appropriately. Use AI health tools for initial exploration and guidance. See a physician for persistent, concerning, or severe symptoms.

How The Wellness A\ Helps

The Wellness A\ can help you explore possible causes of fatigue based on your specific symptoms and context. In consult mode, describe what you're experiencing and receive evidence-based information about potential factors.

The AI can help identify patterns, especially when connected to your wearable data tracking sleep and activity. And if medical evaluation seems warranted, you can book a same-day consultation with a physician.

Understanding why you're tired is the first step to feeling better.

Key Takeaways

• Persistent fatigue isn't normal and deserves attention

• Sleep problems are the most common cause—examine quantity, quality, and timing

• Lifestyle factors including hydration, nutrition, exercise, and substance use significantly affect energy

• Medical conditions like anaemia, thyroid issues, and blood sugar problems can cause fatigue

• Mental health—depression, anxiety, stress—profoundly impacts energy

• Track patterns, optimise basics, and seek medical evaluation for persistent symptoms

Try The Wellness A\ free at thewellnesslondon.com/ai-doctor

FAQ Section

How much tiredness is normal?

Some fatigue after poor sleep, intense activity, or stress is normal. Persistent tiredness that doesn't improve with rest and interferes with daily life is not normal and warrants investigation.

Could my tiredness be serious?

Most fatigue has benign causes, but persistent unexplained tiredness can occasionally indicate significant conditions. This is why medical evaluation matters for fatigue that doesn't resolve with lifestyle adjustments.

What blood tests check for fatigue causes?

Common tests include complete blood count (for anaemia), thyroid function, vitamin B12 and folate, vitamin D, blood glucose, and sometimes inflammatory markers. Your doctor will recommend appropriate tests based on your symptoms.

Does exercise help or hurt when you're tired?

Generally, moderate exercise helps—it improves sleep quality, energy levels, and mood. However, if you're exhausted due to a medical condition, pushing through exercise might not be appropriate. Start gently and see how your body responds.

Can AI tools help identify why I'm tired?

AI health assistants can help explore possible causes based on your symptoms and patterns, particularly when connected to wearable data. They provide a starting point for understanding, though persistent fatigue warrants physician evaluation.

Disclaimer: This content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for personal medical concerns.