Blood Pressure Calculator
Understanding the Two Numbers
Blood pressure readings consist of two numbers (e.g., 120/80 mmHg). They measure the force of blood against your artery walls.
- Systolic (Top Number): The pressure when your heart beats and pushes blood out. This is usually the higher number and is a major risk factor for heart disease in people over 50.
- Diastolic (Bottom Number): The pressure when your heart rests between beats.
Both numbers are important. If either number is high, you may be diagnosed with high blood pressure.
The "Silent Killer"
Hypertension (High Blood Pressure) is often called the "Silent Killer" because it rarely has symptoms. You can walk around with a dangerous reading of 160/100 and feel perfectly fine.
However, over time, this excess pressure damages your arteries, leading to stroke, kidney failure, and vision loss. The only way to know your status is to measure it.
Official Risk Categories (AHA Guidelines)
The American Heart Association updated these guidelines in 2017 to catch problems earlier.
| Category | Systolic | Diastolic |
|---|---|---|
| Normal | Less than 120 | Less than 80 |
| Elevated | 120 - 129 | Less than 80 |
| Stage 1 Hypertension | 130 - 139 | 80 - 89 |
| Stage 2 Hypertension | 140 or higher | 90 or higher |
| Crisis | Higher than 180 | Higher than 120 |
Do you get nervous at the doctor's office? Anxiety can temporarily spike your BP by 10-20 points. If your doctor gets a high reading, they may ask you to measure it at home when you are relaxed to confirm the diagnosis.
How to Get an Accurate Reading
To ensure your home measurement is correct, follow these rules:
- Rest First: Sit quietly for 5 minutes before measuring.
- Feet Flat: Keep both feet on the floor. Do not cross your legs.
- Arm Position: Your arm should be resting on a table at heart level.
- No Caffeine: Avoid coffee or smoking for 30 minutes prior.
Low Blood Pressure (Hypotension)
Is "low" always good? Usually, yes. A reading like 90/60 is considered healthy for many athletes. However, if it drops too low and causes dizziness, fainting, or fatigue, it is called Hypotension and should be checked by a doctor.