Sort the symptom into one of three lanes

Which lane a new symptom belongs in depends less on the symptom itself than on what came with it.

The first lane is 911. Call now if a faint or a dizzy spell comes with chest pain or pressure, trouble breathing, a pounding or irregular heartbeat, weakness or numbness on one side, trouble speaking or seeing, sudden confusion, or a severe headache that arrived out of nowhere. Call if someone fainted and does not wake within a couple of minutes, fainted during exercise or exertion, or fell and hit their head or is bleeding. MedlinePlus also lists fainting itself, and dizziness or weakness that does not go away, among reasons to call 911 or go to the emergency department. A separate article in this series covers the American Heart Association's rule for very high readings; in short, a reading of 180/120 mm Hg or higher together with symptoms such as chest pain, shortness of breath, back pain, numbness, weakness, vision changes, or difficulty speaking means calling 911, not calling the office.

The second lane is a same day call to your care team. This is the lane for a first ever faint with none of the emergency features above, for fainting that keeps happening, for dizziness that started after a new medicine or a dose change, for dizziness that returns day after day, and for any fall, whether or not you were hurt. MedlinePlus puts first time dizziness, dizziness after taking a medicine, and new or worsening symptoms in this group. If the office is closed, the call is usually forwarded to a nurse or health care professional on call, and many practices and insurance plans also run nurse advice lines.

The third lane is a note for your next visit. A moment of lightheadedness when you stand, gone within a few seconds, with no fall and nothing else, belongs here. Write down the date, the time, and what you were doing. A pattern in your notes is far more useful than a vague memory that it "happens sometimes."

When you cannot tell which lane you are in, MedlinePlus offers a plain rule: if you are not sure what to do and you do not have one of the emergency conditions, call your health care professional. A call that turns out to be nothing costs a few minutes.

Lightheaded, spinning, or blacked out: say which one

health care professionals hear "dizzy" dozens of times a week, and the word by itself points nowhere in particular. Three more specific words do.

Lightheaded means you felt faint, as if you might pass out. MedlinePlus describes it as "a feeling that you might faint." It usually means the brain briefly received less blood than it wanted. Common reasons include a sudden drop in blood pressure, dehydration from vomiting, diarrhea, or fever, standing up too quickly, low blood sugar, and blood pressure lowering medicines. This is the type of dizziness most connected to blood pressure treatment, so it is the one your care team most wants to hear about.

Vertigo means you felt that you or the room was spinning or moving. That sensation more often comes from the inner ear than from the brain. It can also be a stroke symptom when it arrives suddenly with trouble walking, double vision, or numbness, which is why sudden loss of balance appears in the current stroke warning list.

Fainting, which health care professionals call syncope, means you actually lost consciousness. MedlinePlus defines it as a brief loss of consciousness caused by a drop in blood flow to the brain, usually lasting less than a couple of minutes with a quick recovery. Losing consciousness is a different event from feeling as if you might, and your care team will treat it differently. If you are not sure whether you passed out, say so, and say whether anyone saw it happen. A witness who can describe how long you were out, whether you jerked or twitched, and how fast you came around is valuable, so bring that person or their phone number.

Dizziness that starts after a medicine change

Dizziness that begins in the days after a new blood pressure medicine or a dose increase is one of the most common reasons people call, and it deserves a same day call. The Centers for Disease Control and Prevention notes that most people taking blood pressure medicines have no side effects, and that when mild ones occur, dizziness is among them, along with headaches, swelling of the legs or feet, and stomach upset. Your health care professional can sort out whether the medicine, dehydration, another drug, or something unrelated is responsible.

The one thing not to do is quietly stop or skip the medicine to see whether the dizziness goes away. The CDC's advice is direct: do not stop taking your current medicine without talking to your doctor or another health care professional first. Blood pressure that climbs after a medicine is dropped is its own problem, and a health care professional who does not know you stopped will be working from wrong assumptions at the next visit.

When you call, have these details ready: the name of the medicine, when you started it or when the dose changed, what time of day you take it, how long after a dose the dizziness tends to arrive, and any other new medicine, including nonprescription pain relievers, decongestants, sleep aids, and allergy pills, plus any alcohol. If you are unsure of names, read them off the bottles. A separate article in this series covers what to ask when your readings run unusually low.

Report every fall, including the ones that did not hurt

Falls are the symptom people most often keep to themselves. The CDC reports that more than one out of four older people falls each year, but less than half tell their doctor. The same page notes that falling once doubles your chances of falling again. A fall that was really a faint or a near faint is information your care team badly needs.

Falls among older adults lead to about 4.5 million emergency department visits a year in the United States, and about 37 percent of people who fall report an injury that needed treatment or limited their activity for at least a day.

When you report a fall, the details health care professionals most want are whether you felt dizzy or lightheaded first or simply tripped, whether you lost consciousness even briefly, whether you hit your head, whether you could get up on your own, and what you had been doing in the previous half hour: standing for a long time, getting out of bed, finishing a large meal, exercising, being out in the heat, or using the toilet. Any fall with a head strike, especially in someone who takes a blood thinner, or any fall followed by confusion or passing out, belongs in the 911 lane.

For adults who report dizziness or a fall, a health care professional may use the CDC's STEADI fall prevention tools. These include measuring blood pressure and pulse after lying down for 5 minutes and again at 1 and 3 minutes after standing, and reviewing every medicine for ones that contribute to falls. In those materials, a drop of 20 mm Hg or more in the top number, or 10 or more in the bottom number, or lightheadedness on standing, counts as abnormal.

What to say when you call: a report you can fill in

Nurses and health care professionals work through a symptom in a fairly predictable order. Answering in that order gets you to a decision faster. Keep this list near your monitor or on your phone.

1. 1 What happened, in one of the three words: lightheaded, spinning, or passed out. If you fell, say so first.
2. 2 When it started, how long each episode lasted, and how many times it has happened. "Twice this week, each about 20 seconds" is the kind of answer that helps.
3. 3 What you were doing right before: standing up, standing for a long time, an hour or two after a meal, exercising, in the heat, coughing, or on the toilet.
4. 4 What else you felt: chest pain or pressure, shortness of breath, a racing or irregular heartbeat, sweating, nausea, weakness or numbness, trouble speaking, vision changes, headache, or confusion. Say clearly if there was nothing else.
5. 5 What your monitor showed, if you could check safely, and what your usual home readings run. Take at least two readings, 1 or 2 minutes apart, and report both rather than picking one. Sit to measure; do not stand at the monitor while dizzy.
6. 6 Every medicine you took today and when, including nonprescription pain relievers, decongestants, and sleep aids, plus any alcohol. Mention any dose you missed this week and anything started or changed in the past month, including vitamins and supplements, so the health care professional has the full picture.
7. 7 Whether you fell, whether you hit your head, and whether you were hurt.
8. 8 Anything recent that could have left you dehydrated or run down: vomiting, diarrhea, fever, eating or drinking less than usual, hot weather, or a hard workout.
9. 9 Your pharmacy and a phone number where you can be reached for the rest of the day.

If you have a monitor with memory or a written log, have it in front of you. Nurse advice lines typically ask about the reading, your symptoms, and your medicines, and then tell you whether to recheck, come in, or go to the emergency department. Write down what you are told, including whom to call if things change and when to check in again.

Keep a small notebook or a note on your phone in which every episode gets a line with the date, time, the word that best describes it, and the reading. When your health care professional asks how often this happens, you will have an answer instead of a guess.

If you are the one helping someone who fainted

care partners and household members are often the ones making the call. MedlinePlus describes the first steps. Check that the person is breathing; if they are not, or they do not respond, call 911 and follow the dispatcher's instructions. If they are breathing, lay them flat and raise their feet about 12 inches above heart level, loosen anything tight at the neck, and turn them on their side if they vomit so they do not choke. Let them rest lying down for 10 to 15 minutes in a cool, quiet spot before trying to get up.

Note the time the person went down and the time they came around. A faint lasting longer than a couple of minutes is a 911 call. If the person shows any stroke sign as they recover, call 911 even if the symptom fades. The American Stroke Association's current warning list, remembered as B.E. F.A.S.T., covers sudden loss of balance, sudden vision change, face drooping, arm weakness, and speech difficulty, with T for time to call 911. Call rather than driving to the hospital; an ambulance crew can begin treatment on the way, and treatment for stroke works best in the first hours, so the time symptoms began is one of the first things the crew will ask.

Steps you can take while you wait

Some practical steps carry no risk and come straight from the CDC's fall prevention materials. Get out of bed in stages: sit up first, then sit on the edge of the bed for a moment, then stand. Take your time rising from a chair. Have something to hold when you stand, and sit for tasks such as showering, dressing, or kitchen work if standing brings on lightheadedness. The CDC's most important line is also the simplest: do not walk if you feel dizzy. Sit or lie down until it passes, then get up slowly.

The same CDC brochure suggests drinking 6 to 8 glasses of water or other low calorie fluids a day and avoiding very hot baths or showers. Those tips apply unless your care team has given you a fluid limit, which is common with heart failure or kidney disease, so check before changing how much you drink.

Blood pressure thresholds in pregnancy are different and lower. Anyone who is pregnant should use the numbers and instructions from their obstetric care team and should call promptly about dizziness, fainting, a high reading, headache, vision changes, or upper abdominal pain rather than applying the general rules here.

Other changes belong to your health care professional: adding salt, adjusting or adding any medicine, or using compression garments. The CDC brochure's suggestion to ask whether any of your medicines should be reduced or stopped is the right frame. You raise the question with the full picture in hand, and the health care professional answers it.