Giddiness or fainting spells refer to episodes of dizziness, lightheadedness, or brief loss of consciousness. These occur when the brain temporarily receives insufficient blood flow or oxygen. While occasional episodes may be harmless, recurring spells can signal an underlying heart condition that requires medical evaluation. Recognising the symptoms and causes can help you determine when to seek medical advice.
MBBS (SG)|MRCP (UK)|MMed (Internal Med) (SG)|FAMS (Cardiology, SG)
Common symptoms you may experience during or before a giddiness or fainting episode include:
Several factors can trigger giddiness or fainting spells:
Standing up too quickly from sitting or lying down can cause blood to pool in your legs. This reduces blood flow to your brain temporarily, leading to dizziness or fainting.
Not drinking enough fluids reduces your blood volume, making it harder for your heart to pump blood to your brain. This commonly occurs during hot weather, illness, or after intense exercise.
When your blood glucose drops too low, your brain lacks the fuel it needs to function properly. This often happens if you skip meals, diet excessively, or have diabetes.
Irregular heartbeats, including excessively fast or slow heart rates, can reduce the amount of blood pumped to the brain.
Some medicines, particularly those for blood pressure, heart conditions, or depression, can lower your blood pressure or affect your heart rate. This increases your risk of feeling dizzy or faint.
Intense emotional reactions can trigger changes in your breathing and heart rate. This can lead to feeling lightheaded or faint, particularly in stressful situations.
Remaining upright for extended periods, especially in hot or crowded environments, can cause blood to pool in your legs. This reduces blood return to your heart and brain.
As you get older, your blood vessels become less flexible and your reflexes slower. This makes you more susceptible to blood pressure changes that can cause dizziness.
Different types of fainting or giddiness can occur based on their underlying causes:
This is the most common type, triggered by emotional stress, pain, or prolonged standing. Your body overreacts by slowing your heart rate and dilating blood vessels, reducing blood flow to your brain.
This occurs when your blood pressure drops significantly upon standing up. Your body fails to adjust quickly enough to the position change, causing dizziness or fainting.
This type results from heart rhythm abnormalities or structural heart problems. It can be more concerning as it indicates your heart isn’t pumping blood properly to your brain.
This happens in response to specific triggers such as coughing, urinating, or having blood drawn. These activities temporarily affect blood flow or pressure in your body.
To determine the cause of your giddiness or fainting episodes, several diagnostic tests may be used to assess your heart function and identify potential rhythm or circulation problems:
This test records your heart’s electrical activity through small sensors placed on your chest. It can detect irregular heart rhythms or other heart problems that might cause fainting.
Your blood pressure is measured in different positions, including lying down and standing up. This helps identify if position changes are causing your symptoms.
A portable device worn for 24 hours or longer that continuously records your heart’s electrical activity during normal daily activities.
An ultrasound scan that produces images of your heart, allowing assessment of heart structure and function to help identify causes of fainting.
You walk on a treadmill while your heart rate, blood pressure, and ECG are monitored to assess how your heart responds to physical activity.
Treatment approaches focus on addressing the underlying heart conditions or rhythm problems that contribute to your fainting episodes:
When medication and lifestyle changes aren’t sufficient to control heart rhythm problems causing fainting, procedural interventions may be necessary:
Consult our MOH-accredited specialist for a comprehensive diagnosis & personalised treatment plan today.
Preventing giddiness and fainting episodes involves staying well-hydrated, rising slowly from sitting or lying positions, and wearing compression stockings if recommended. Avoiding known triggers such as prolonged standing, hot environments, or skipping meals can significantly reduce episode frequency.
See a cardiologist if you experience:
Brief fainting episodes typically don’t cause permanent damage to your heart or brain. However, injuries from falling during an episode can occur, which is why identifying and treating the underlying cause is necessary.
Response to treatment varies depending on the underlying cause, but many people notice improvement within weeks of starting appropriate medication or lifestyle changes. Heart rhythm devices often provide immediate symptom relief.
Most people can continue exercising once their condition is properly managed, though you may need to modify intensity or type of activity initially. Your doctor will provide specific guidance based on your individual situation and underlying heart condition.
Modern cardiac devices allow most people to return to their normal activities, though you’ll need to avoid strong magnetic fields and inform medical staff about your device before procedures. Most household appliances and mobile phones are safe to use normally.
Dr. Kua is a senior consultant cardiologist specialised in interventional cardiology and is the medical director at Carrington Cardiology.
Prior to this, he served as an International Cardiology Fellow and Honorary Consultant at Hammersmith Hospital Imperial Healthcare Trust, where he gained valuable experience in various prestigious healthcare institutions.
Mount Elizabeth Medical Centre
3 Mount Elizabeth, #12-02 Medical Centre
Singapore 228510
Mon to Fri: 09:00am – 05:00pm
Sat: 09:00am – 12:30pm
Sun & Public Holidays: Closed
Leave us a message and we’ll get back to you shortly
Mount Elizabeth Medical Centre
3 Mount Elizabeth, #12-02 Medical Centre
Singapore 228510
Mon to Fri: 09:00am – 05:00pm
Sat: 09:00am – 12:30pm
Sun & Public Holidays: Closed
