Common Causes of Dizziness
1. Inner-Ear / Vestibular Causes (Vertigo)
BPPV (Benign Paroxysmal Positional Vertigo) is the most common cause of true vertigo — brief spinning episodes triggered by head position changes. Other inner-ear causes include vestibular neuritis, labyrinthitis and Ménière disease.
2. Dehydration
Common clues include thirst, dark urine, dry mouth, reduced urine output and light-headedness on standing. Particularly relevant in hot weather, fever, vomiting or diarrhoea.
3. Low Blood Pressure (Orthostatic Hypotension)
Dizziness or light-headedness occurring after standing suddenly or prolonged standing. Can be caused by dehydration, blood loss, certain medicines and underlying heart or autonomic conditions.
4. Anaemia
Low haemoglobin reduces oxygen delivery to the brain. Dizziness may accompany fatigue, breathlessness, palpitations, reduced exercise capacity and pallor.
5. Blood Glucose Problems
Low glucose (hypoglycaemia) may cause dizziness, sweating, trembling, hunger, weakness and confusion — especially in people taking glucose-lowering medication. High glucose can cause dehydration and fatigue.
6. Migraine
Vestibular migraine can cause prominent dizziness even when headache is mild or absent. Often underdiagnosed.
7. Medicines
Blood-pressure medicines, sedatives, anti-anxiety medicines, antidepressants and anti-seizure medicines can all contribute to dizziness, particularly when starting a new medication or after dose changes.
8. Heart Problems
Dizziness or near-fainting can occasionally result from arrhythmias, very low blood pressure or structural heart disease. Palpitations, chest discomfort or actual fainting significantly increases concern.
9. Neurological Causes
Less commonly, acute dizziness with other neurological symptoms can arise from stroke, transient ischaemic attack (TIA) or multiple sclerosis. Neurological symptoms change the clinical urgency completely.
⚠️ When Should You Seek Medical Care?
Seek urgent medical attention if you experience any of the following:
- New weakness or numbness on one side of the body
- Slurred speech or facial drooping
- Double vision or sudden loss of vision
- Severe new difficulty walking or falls
- Sudden severe headache accompanying dizziness
- Loss of consciousness or near-fainting
- Chest pain or severe palpitations with dizziness
- New confusion or altered consciousness
- Significant head injury preceding dizziness
- New hearing loss with severe continuous vertigo
Which Laboratory Tests May Be Considered?
Clinical note: Laboratory tests should be selected by a doctor based on your symptoms, history and clinical examination. Not every person requires all of the tests listed below.
| Test | Why a Doctor May Consider It |
|---|---|
| CBC | To identify anaemia as a cause of light-headedness |
| Blood Glucose | To detect hypoglycaemia or significant hyperglycaemia |
| HbA1c | Longer-term glucose assessment when diabetes is suspected |
| Electrolytes | Low sodium or potassium can cause dizziness and weakness |
| Kidney Function Tests | When dehydration, renal disease or metabolic disorder is suspected |
| TSH | Thyroid disorders can occasionally contribute to dizziness and balance issues |
| Ferritin / Iron Studies | When iron deficiency contributing to anaemia is suspected |
| Vitamin B12 | B12 deficiency can cause balance problems and neurological symptoms |
Frequently Asked Questions
What is the most common cause of vertigo?
BPPV (Benign Paroxysmal Positional Vertigo) is the most common cause of true vertigo. It causes brief spinning episodes triggered by head position changes and can often be treated with a repositioning manoeuvre.
Can low blood pressure cause dizziness?
Yes. Orthostatic hypotension — a drop in blood pressure on standing — is a common cause of dizziness and light-headedness.
Should I take a blood test for dizziness?
Not necessarily first. Many common dizziness disorders require blood pressure measurement, ear and neurological examination, ECG and positional testing rather than blood tests. Your doctor will decide which investigations are appropriate.
QXL Diagnostic Support
QXL Diagnostics provides CBC, blood glucose, electrolytes, thyroid and other laboratory investigations when your doctor recommends testing for dizziness. Home collection available across Bengaluru.
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Medical Review
Medically reviewed by: Dr. Shantakumar Muruda, MD - Medical Biochemistry; Founder & CEO, QXL Diagnostics Super Speciality Lab, Bengaluru
Last medically reviewed: 2026-09-11
Clinical reference framework:Harrison's Principles of Internal Medicine; Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics; and relevant specialty guidance as clinically appropriate.
Medical Disclaimer: This information is intended for general health education and does not diagnose an individual medical condition. It does not replace consultation, diagnosis or treatment by a qualified healthcare professional. Seek urgent medical attention for severe, sudden or rapidly worsening symptoms or any emergency warning signs described above.