What to do when someone faints
No matter the cause of fainting, if someone suddenly appears sweaty or has a vacant look in her eyes, suggest she sit down and bend over so her head is lower than her chest. If she’s willing, lying down is even better. If she starts to fall, try helping her down so she won’t get hurt.
Never keep her upright, because this may continue to keep blood from getting to the brain. Once the head is as low as or lower than the heart, the victim should regain consciousness, albeit probably in a groggy state.
Have her stay in that position for several minutes until the fainting symptoms subside. Check her pulse and blood pressure if you have a cuff. Make sure they’re normal before she tries to get up. Let her sit for a few minutes, and if there are no symptoms, she could slowly try to stand.
If the fainting symptoms recur, help her lower herself again, let the symptoms subside, and slowly try once more.
If the person is able to sit up for a few minutes and eventually stand, the cause is likely vasovagal (associated with a temporary fall in blood pressure), especially if you can pinpoint a trigger, such as a fright or the sight of blood. If you’re not sure it’s vasovagal, call emergency services or a doctor.
When it may be dangerous
Often, the likely reason for the fainting is pretty obvious, such as if the person has lost a lot of blood or is dehydrated from vomiting.
However, there are some red flags that indicate that something serious is going on and that expert treatment is needed. These include sudden onset; heart palpitations; passing out while exercising; severe headaches; excruciating back or stomach pain; and double vision.