You probably know someone who takes a pill for their blood pressure.
Many people live with the condition for years and feel absolutely nothing. That is a big part of why doctors call it the silent killer.
Nearly half of American adults have high blood pressure, and in 2024 it was a primary or contributing cause of 680,179 deaths, according to the CDC. Only about one in four has the condition under control.
The reason it slips past so many people is simple. Hypertension usually causes no symptoms until it begins to damage the heart, kidneys or brain.
Also read: 7 signs your body may be chronically dehydrated, and most people overlook them
That is why it is often picked up by chance, during a routine checkup at a pharmacy or a doctor's office.
But the condition is not silent at every level. At very high readings, or during a sudden spike, the body often does send signals.
The trouble is that they look like everyday complaints and get blamed on stress, allergies or a rough night's sleep.
Where the silent killer stops being silent
Doctors call it a hypertensive crisis when a reading reaches 180/120 mm Hg or higher, according to the Cleveland Clinic.
Also read: 8 warning signs of a blood clot most people mistake for a sore muscle
At that level, pressure can begin to injure blood vessels and organs within minutes.
The warning signs below are often what finally sends a person to the hospital. They are also what readers most often brush off as something else.
Eight warning signs the body may send
1. A sudden, pounding headache. A severe headache that over the counter painkillers barely touch is one of the clearest signals during a hypertensive crisis, Mayo Clinic says. It usually comes with other symptoms on this list, not alone.
2. Shortness of breath. Feeling winded without exertion can mean the heart is struggling to push blood against very high pressure.
Also read: APA survey: 77% of Americans are stressed about money, and nearly half have stopped seeing friends
Mayo Clinic lists it among the symptoms that should prompt a 911 call when the reading is 180/120 or higher.
3. Chest pain. Pain or tightness in the chest at a crisis-level reading can signal that the heart muscle is not getting enough blood. Treat it as an emergency, not something to walk off.
4. Vision changes. Sudden blurred vision, loss of vision or eye pain can mean pressure has damaged the small vessels in the retina.
The Cleveland Clinic lists these among the signs of a hypertensive emergency.
Also read: Cervical cancer is almost fully preventable, yet two in three women have never been screened
5. Nosebleeds. Most nosebleeds have nothing to do with blood pressure.
But a nosebleed during a sudden spike, or one that comes with other symptoms, is one of the warning signs the Cleveland Clinic flags for severe hypertension.
6. Dizziness or feeling off balance. Dizziness is easy to blame on skipping lunch or standing up too fast. During a hypertensive emergency it can mean disturbed blood flow to the brain.
7. Nausea or vomiting. Mayo Clinic lists nausea and vomiting among the symptoms of a hypertensive crisis.
Also read: One in five babies missed their first measles shot, and cases climbed 40%
On its own it is rarely blood pressure. Paired with a severe headache or vision changes, it should not be ignored.
8. Confusion or trouble speaking. Sudden confusion, trouble finding words or slurred speech can be the brain reacting to very high pressure.
The Cleveland Clinic groups altered mental status with stroke signs like facial droop and sudden weakness, and says this is an emergency.
When to seek emergency care
If a home reading shows 180/120 mm Hg or higher and any of the symptoms above are present, the Cleveland Clinic says to call 911 immediately.
If the reading is that high but there are no symptoms, rest for a few minutes, recheck, and contact a doctor if it stays up.
If readings sit above the normal range but below the crisis threshold, and symptoms like fatigue, headaches or dizziness keep coming back, book an appointment with a primary care doctor.
This article is made and published by Mie Hermansen, who may have used AI in the preparation.