Fear of blood can influence ordinary healthcare and everyday situations. You may become anxious days before a blood test, avoid looking at an injury, ask somebody else to deal with first aid or turn away from television or photographs that involve blood.

For somebody else, the difficult part is physical. They may initially feel tense or anxious and then notice warmth, nausea, visual dimming, weakness or a sudden need to sit or lie down.

You may still complete the appointment or deal with the injury, but doing so does not show how much anticipation, monitoring or practical preparation was involved.

Blood-related fear can produce symptoms such as:

• A stronger or faster heartbeat
• Sweating, trembling or warmth
• Nausea or stomach discomfort
• Dizziness or light-headedness
• Weakness or a feeling that your legs may give way
• Changes in vision or hearing before a faint
• A strong urge to sit or lie down
• Actual fainting in some people

Some people with blood-injection-injury phobia are prone to vasovagal syncope, in which blood pressure and heart rate can fall enough to reduce blood flow to the brain and cause fainting.

That does not mean every dizzy feeling will lead to unconsciousness, and it does not mean every episode of fainting is phobic. Recurrent, unexplained or new fainting should be medically assessed rather than assumed to be caused by haemophobia.

The fear can centre on different expectations.

You may worry about:

• Fainting and injuring yourself when you fall
• Losing control in front of other people
• Seeing an injury that feels overwhelming
• A small amount of blood meaning something serious
• Having a blood test or medical procedure
• Feeling sick or disgusted
• Seeing somebody else bleed
• Not being able to help if an injury occurs
• Becoming trapped in a medical situation once it starts

For some people, disgust is as prominent as fear.

For others, the most difficult part is not blood itself but the expectation of becoming faint or helpless in front of it.

Haemophobia can affect how you prepare for or respond to blood-related situations.

You might:

• Postpone blood tests or medical appointments
• Look away whenever blood is visible
• Leave the room during first aid
• Avoid certain healthcare procedures
• Ask to lie down during blood tests
• Depend on somebody else to manage minor injuries
• Avoid jobs, courses or activities where blood may be present
• Repeatedly check whether you feel faint
• Avoid media that may show injuries

Some of these arrangements may be sensible, particularly if you have a known fainting tendency and a healthcare professional has advised practical precautions.

The useful distinction is whether the arrangement helps manage a genuine physiological need or whether fear has made more and more situations feel unavailable.

Blood fear can have consequences beyond discomfort.

Somebody may delay investigations, vaccinations or other healthcare because they fear the blood-related part of the procedure. Another person may avoid first-aid training, particular careers or situations where they could be expected to help somebody who is injured.

For someone else, the restriction is mainly mental. They attend appointments but spend days beforehand imagining fainting, losing control or seeing blood.

A useful question is:

What would I be doing differently if blood-related fear had less influence?

Perhaps you would attend the test, treat a minor cut, support somebody who is injured or remain present during an ordinary medical situation without your whole attention being taken over by the possibility of fainting.

Those practical changes help describe what you want back.

You do not need to look at blood or provoke dizziness before discussing the fear with a therapist.

One ordinary example can be enough: what the situation was, what you expected, what happened in your body, whether you have a genuine history of fainting, what you did to feel safer and what you would have preferred to be able to do.

If you have unexplained fainting, significant medical symptoms or concerns about a procedure, those should be discussed with an appropriate healthcare professional as well.