A blood pressure of 113/66 is a good reading. Both numbers fall within the normal range, which the American Heart Association defines as below 120/80 mm Hg. In fact, 113/66 sits comfortably in what some guidelines call the “optimal” zone, meaning it’s associated with the lowest cardiovascular risk.
What 113 and 66 Each Tell You
The top number (113) is your systolic pressure, the force against your artery walls when your heart beats. The bottom number (66) is your diastolic pressure, the force between beats when your heart relaxes. Both numbers matter, but systolic pressure tends to be a stronger predictor of heart disease and stroke risk, especially as people age. Systolic pressure naturally rises over the decades, making it the more common driver of hypertension in older adults.
At 113 systolic, you’re 7 points below the threshold where a reading would shift from “normal” to “elevated” (120-129 systolic). And at 66 diastolic, you’re well under the 80 mm Hg cutoff. That gives you a healthy margin on both counts.
How Blood Pressure Categories Work
The current classification system, updated in the 2025 AHA/ACC guidelines, breaks blood pressure into four categories:
- Normal: below 120 systolic and below 80 diastolic
- Elevated: 120 to 129 systolic with diastolic still below 80
- Stage 1 hypertension: 130 to 139 systolic or 80 to 89 diastolic
- Stage 2 hypertension: 140 or higher systolic or 90 or higher diastolic
If your systolic and diastolic numbers fall into different categories, the higher category applies. With 113/66, both numbers land in the normal range, so there’s no conflict.
These thresholds apply across all adult age groups. Earlier guidelines used different cutoffs for people over 65, but the current framework treats all adults the same.
Is 66 Diastolic Too Low?
A diastolic reading of 66 sometimes raises questions because it’s on the lower end. Low blood pressure (hypotension) is generally defined as a reading below 90/60 mm Hg, and 113/66 is well above that. Most doctors consider blood pressure “too low” only when it causes symptoms like dizziness, lightheadedness, fainting, or unusual fatigue.
What matters more than any single number is a sudden drop. A decrease of just 20 mm Hg in systolic pressure, from 110 down to 90 for example, can cause dizziness or fainting. So if your readings are consistently around 113/66 and you feel fine, there’s no cause for concern. If you’re noticing symptoms like standing up and feeling woozy, that’s worth mentioning at your next checkup even if the numbers look normal on paper.
Why a Single Reading Isn’t the Full Picture
Blood pressure fluctuates throughout the day. It typically starts rising a few hours before you wake up, peaks around midday, and drops in the late afternoon and evening. It’s lowest during sleep. Stress, caffeine, a full bladder, and even the anxiety of being in a doctor’s office (known as white coat hypertension) can temporarily push readings higher.
A single reading of 113/66 is encouraging, but the pattern over time tells a more complete story. If you’re tracking at home, take readings at the same time each day for a week or two to get a reliable average.
Getting an Accurate Reading at Home
Small details in how you measure can swing a reading by 10 points or more. The CDC recommends the following for accuracy:
- Sit quietly for at least 5 minutes with your back supported before measuring.
- Rest your arm with the cuff at chest height on a table or armrest.
- Keep both feet flat on the floor, legs uncrossed.
- Place the cuff on bare skin, not over clothing, and make sure it’s snug without being tight.
- Skip food, drinks, and exercise for 30 minutes beforehand.
- Empty your bladder before sitting down.
- Don’t talk during the measurement.
If your at-home readings consistently come back in the range you’re seeing, you can feel confident the number is real and not an artifact of technique.
During Pregnancy
If you’re pregnant and seeing 113/66, that’s a reassuring number. High blood pressure during pregnancy is diagnosed at 140/90 or above on two readings taken at least four hours apart, and severe hypertension is defined as 160/110 or higher. A reading of 113/66 is well below those thresholds. That said, blood pressure can change quickly during pregnancy, so regular monitoring is still important.
Keeping Your Numbers in This Range
A reading of 113/66 means you’re in a good position, and the goal is to stay there. The lifestyle factors that keep blood pressure healthy are the usual suspects: regular physical activity, a diet rich in fruits, vegetables, and whole grains with moderate sodium, maintaining a healthy weight, and managing stress. These aren’t just relevant once your numbers climb; they’re what prevent the gradual upward drift that happens with age for most people. Systolic pressure in particular tends to creep up over the years, so the habits you maintain now pay off for decades.