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Have you wondered why am I so tired all the time, even after a night of sleep? Persistent tiredness is one of the most common complaints people bring to their doctor. Feeling low on low energy can range from a temporary spell after a stressful week to an early sign of an underlying illness. Understanding the common fatigue causes, what to watch for, and when to get medical help helps people take the right next step for their health.
Synopsis
- What Counts As Fatigue?
- Common Causes Of Fatigue
- More About Common Problems People Ask
- When Fatigue Is A Red Flag, Urgent Signals
- How Doctors Approach Persistent Tiredness
- Common Tests And What They Check
- Practical Steps People Can Try Now
- When To See A Specialist And Where To Go
- When Fatigue Needs Specialist Help
- Conclusion
What Counts As Fatigue?
Fatigue is more than feeling sleepy. It is a sustained lack of energy, mental slowness, or physical exhaustion that interferes with daily life. Terms you may hear, exhaustion, tiredness, fatigue, or simply tiredness, describe similar experiences. Clinicians ask how long the problem has lasted, whether sleep feels refreshing, and what other symptoms are present to separate normal tiredness from medical fatigue.
Common Causes Of Fatigue
There are many causes of fatigue. Most fall into a few broad groups: lifestyle, medical conditions, medications, and mental health. Below is a clear table that helps sort the usual suspects.
|
Category |
Examples |
Why It Causes Fatigue |
|
Lifestyle |
Poor sleep habits, shift work, overwork, alcohol, and poor diet |
Inadequate restorative sleep and energy intake lower daily reserves |
|
Sleep Disorders |
Obstructive sleep apnoea, restless legs, insomnia |
Fragmented sleep or low-quality sleep causes daytime low energy |
|
Mental Health |
Depression, anxiety |
Low mood and stress reduce motivation and energy |
|
Endocrine/Metabolic |
Hypothyroidism, diabetes, and adrenal insufficiency |
Hormone imbalances disrupt energy production |
|
Infections |
Mononucleosis, TB, post-viral fatigue (including long COVID) |
Ongoing immune activation increases tiredness |
|
Cardiopulmonary |
Heart failure, chronic lung disease |
Poor oxygen delivery causes exertional fatigue |
|
Haematological |
Anaemia |
Low red cells mean less oxygen to tissues - what causes tiredness and lack of energy |
|
Chronic Diseases |
Kidney disease, liver disease, and autoimmune disorders |
Systemic illness drains energy and appetite |
|
Medications |
Antihistamines, some blood pressure meds, antidepressants |
Side effects commonly include drowsiness and fatigue |
|
Neurological |
Multiple sclerosis, Parkinson’s disease |
Direct effects on the nervous system cause fatigue |
More About Common Problems People Ask
Sleep Problems and Lifestyle
Many people who ask why I am always tired find the answer in their sleep quality. Even if total hours look adequate, frequent awakenings or untreated sleep apnoea leave a person feeling unrefreshed. Simple changes, fixed sleep schedule, reducing screen time before bed, avoiding heavy late meals and alcohol, help a lot.
Mental Health
When someone asks why I would be so tired with no clear physical cause, low mood or anxiety is often the explanation. Depression commonly causes severe fatigue and loss of interest in activities. Speaking to a clinician about mood and stress is an important step.
Medical Conditions
Several illnesses produce persistent tiredness. What causes extreme fatigue can include anaemia, hypothyroidism, chronic infections, and heart or lung disease. Blood tests often uncover treatable causes such as low haemoglobin or an underactive thyroid.
Post-Infectious and Chronic Fatigue
After some infections, people develop long-lasting tiredness that may fit the pattern called chronic fatigue. If someone wonders what causes extreme fatigue months after an illness, specialised clinics and a stepwise medical review can help.
When Fatigue Is A Red Flag, Urgent Signals
Most tiredness is not an emergency, but there are fatigue red flags to watch. Seek prompt medical help if fatigue comes with:
-
Unintentional weight loss, night sweats or persistent fever (possible infection or cancer).
-
Chest pain, breathlessness at rest, or fainting (heart or lung problems).
-
New neurological signs (weakness, numbness, balance problems).
-
Sudden and severe worsening of energy or inability to perform routine tasks.
-
Severe shortness of breath or sudden confusion.
These signs can suggest a severe underlying disease and require urgent assessment.
How Doctors Approach Persistent Tiredness
When someone reports persistent tiredness, clinicians follow a stepwise approach:
-
Detailed history: sleep, work, mood, medication, recent infections, diet, and alcohol.
-
Physical exam focusing on the heart, lungs, thyroid, and neurological signs.
-
Basic tests: CBC (checks for anaemia), thyroid function, blood glucose, kidney and liver tests, and inflammatory markers.
-
Targeted tests based on clues: sleep study for suspected sleep apnoea, iron studies for iron-deficiency anaemia, and imaging if infection or malignancy is suspected.
-
Medication review and mental-health screening.
This approach helps detect common, treatable causes of fatigue and avoid unnecessary tests.
Common Tests And What They Check
|
Test |
Why It’s Done |
What It Can Show |
|
CBC (full blood count) |
Routine check |
Anaemia or infection |
|
Thyroid function tests |
When fatigue, weight change, and cold intolerance are present |
Hypothyroidism |
|
Blood glucose / HbA1c |
Fatigue with polyuria or risk factors |
Diabetes or poor glycaemic control |
|
Kidney/liver tests |
General systemic illness |
Organ dysfunction causing low energy |
|
Vitamin B12 / folate |
If neuropathy or macrocytic anaemia is suspected |
B12 deficiency linked to fatigue |
|
CRP/ESR |
Inflammatory markers |
Infection, autoimmune disease |
|
Sleep study (polysomnography) |
Loud snoring, daytime sleepiness |
Sleep apnoea diagnosis |
Practical Steps People Can Try Now
While waiting for a medical review, these practical measures often help reduce exhaustion, tiredness, and fatigue:
-
Improve sleep hygiene: fixed sleep–wake times, cool dark bedroom, limit screens before bed.
-
Small, regular meals with balanced nutrients to avoid energy dips.
-
Gentle daily activity, short walks often boost energy more than long rests.
-
Limit caffeine after mid-afternoon and avoid alcohol near bedtime.
-
Review medications with the clinician or pharmacist for side effects that cause fatigue.
-
Manage stress with simple breathing exercises or short periods of relaxation.
These steps alone may answer why am I so tired all the time for many people.
When To See A Specialist And Where To Go
If initial tests are normal but fatigue persists, referral to internal medicine, sleep medicine, endocrinology, or psychiatry may be needed. For residents in the region looking for comprehensive care, the internal medicine teams at Manipal Hospitals Salem provide systematic evaluation of fatigue causes and coordinate specialist referrals.
When Fatigue Needs Specialist Help
|
Feature |
Action |
|
Ongoing severe fatigue despite normal basic tests |
Refer to an internal medicine or specialist clinic |
|
Suspected sleep apnoea |
Sleep study and respiratory or ENT referral |
|
Unexplained weight loss/fever |
Urgent imaging and specialist input |
|
Mood disorder suspected |
Mental health referral for therapy/medication |
Conclusion
Fatigue is common and usually fixable, but persistent or severe tiredness requires a thoughtful medical review. From simple lifestyle factors to treatable medical conditions, many causes of fatigue can be identified and managed. If someone keeps asking why am I so tired all the time or experiences causes of extreme fatigue, a clear, stepwise assessment helps find answers and restore energy.
For a thorough evaluation of persistent tiredness, book an appointment with the internal medicine team at Manipal Hospital Salem. Their specialists will run the necessary tests, coordinate care across disciplines, and create a personalised plan to help restore energy and quality of life.
FAQ's
Poor sleep quality, sleep disorders such as sleep apnoea, depression, or medical conditions like hypothyroidism are common reasons. A medical review helps identify the cause.
Sudden onset of extreme tiredness can follow infections, significant blood loss, heart problems, or metabolic crises. Seek prompt medical attention if severe or rapid.
If tiredness lasts more than two weeks and affects daily life despite basic self-care, consult a clinician for initial tests.
Improved nutrition often helps, but if underlying medical causes exist, diet alone may not be enough. Combine healthy eating with medical advice.
The internal medicine specialists at Manipal Hospital Salem offer comprehensive evaluation and can arrange sleep studies, blood tests, and specialist referrals as required.
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