About this topic
A vasovagal response happens when the body overreacts suddenly to some stimuli. Some people react to the sight of blood or a needle. Others react to fear of pain or extreme emotional distress. Your blood pressure and heart rate drop very quickly. This lowers how much blood flows to the brain. You may faint or have a short blackout. ‚
What are the causes?
A vasovagal response is most often the cause for passing out or nearly doing so. It happens as a response to many types of triggers. These may include: ‚
- Blood and needles
- Pain or seeing someone who is hurt
- Emotions like stress or fear
- Signs of illness like fevers, low blood sugar, or fluid loss
- Standing for too long in one position or getting up too quickly
- Straining to have a bowel movement
- Drugs that change your blood pressure
What are the main signs?
You may notice some signs before you faint. Before you passed out, you may have: ‚
- Felt lightheaded
- Turned pale
- Been shaky
- Felt hot or sweaty
- Been clammy with a cold sweat
- Had an upset stomach or nausea
- Noticed a change in your eyesight like dim or blurred eyesight, tunnel vision, dilated pupils, or seeing spots in front of the eyes
- Noticed hearing loss or ringing in the ears
How does the doctor diagnose this health problem?
Your doctor will take your history. Talk to the doctor about: ‚
- All the drugs you are taking. Be sure to include all prescription, over the counter, and herbal supplements. Tell the doctor if you have any drug allergy. Bring a list of drugs you take with you.
- What you were doing and how you felt before you fainted.
Your doctor will do a physical exam and may order: ‚
- Lab tests
- Electrocardiogram (ECG)
- Heart tests like an echocardiogram, stress test, or holter monitor
- CT or MRI scan
- Tilt table test
Based on these results, your doctor may order more heart tests like: ‚
- Electrophysiology studies to see if a pacemaker or an implantable cardiac defibrillator (ICD) is needed
- Cardiac cath to look for problems with the hearts blood flow
How does the doctor treat this health problem?
- Sometimes the doctor will only want to rule out a more serious problem. No other care may be needed.
- Your doctor may want to adjust some of your drugs, especially if you take drugs for high blood pressure.
What drugs may be needed?
The doctor may order drugs to: ‚
- Reduce passing out
- Relieve dizziness
- Control blood pressure
What can be done to prevent this health problem?
- Find out your triggers. Triggers are things that you notice just before you pass out. These may be seeing blood, getting up too quickly, or high temperatures. Try to avoid them.
- Drink 6 to 8 glasses of water each day.
- Talk to your doctor about how much salt is in your diet. Ask if you need more or less.
- If you feel like you might faint, lie down or ease yourself to the floor. Raise your legs. You may want to sit and put your head down between your legs. Both of these may help to avoid falling.
- Cross your legs and tighten your leg muscles to help keep your blood pressure from dropping. This might also help before you get a shot or have blood drawn. Remain seated 15 to 30 minutes before rising again to ensure you dont faint again.
- Get up slowly from a sitting or lying down position. Sit on the edge of the bed and take deep breaths before getting out of bed.
- Move your legs often if you need to sit or stand in one position for a long time.
- Do foot exercises. Pump your foot up and down from the ankle or make small circles with your foot.
- Wear comfortable stockings that stretch to help with blood flow.
When do I need to call the doctor?
Activate the emergency medical system right away if you have signs of a heart attack or stroke. Call 911 in the United States or Canada. The sooner treatment begins, the better your chances for recovery. Call for emergency help right away if you have: ‚
- Signs of heart attack:
- Chest pain
- Trouble breathing
- Fast heartbeat
- Feeling dizzy
- Signs of stroke:
- Sudden numbness or weakness of the face, arm, or leg, especially on one side of the body
- Sudden confusion, trouble speaking or understanding
- Sudden trouble seeing in one or both eyes
- Sudden trouble walking, dizziness, loss of balance or coordination
- Sudden severe headache with no known cause
Call your doctor if you have: ‚
- Headache not helped by pain drugs
- You hit your head after fainting
- You have another fainting event
- You are not feeling better in 2 to 3 days or you are feeling worse
Where can I learn more?
Dysautonomia Information Network ‚
http://www.dinet.org/NCS/ncs.htm ‚
Consumer Information Use and Disclaimer
This information is not specific medical advice and does not replace information you receive from your health care provider. This is only a brief summary of general information. It does NOT include all information about conditions, illnesses, injuries, tests, procedures, treatments, therapies, discharge instructions or life-style choices that may apply to you. You must talk with your health care provider for complete information about your health and treatment options. This information should not be used to decide whether or not to accept your health care providers advice, instructions or recommendations. Only your health care provider has the knowledge and training to provide advice that is right for you. ‚
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Copyright ‚ © 2015 Clinical Drug Information, LLC and Lexi-Comp, Inc. ‚