Blood Pressure 159 Over 40–123: Which Are OK?
With an upper value of 159, the answer depends on your lower number. Here are all readings, sorted by what they mean.
On its own, a systolic (upper) value of 159 mmHg is Hypertension stage 1 by the international categories (2023 ESH guideline) and Stage 2 hypertension under the 2025 AHA/ACC guideline. The worse of your two numbers decides the category, so a raised diastolic (lower) value moves a 159 reading up: from 159/100 it counts as stage 2, from 159/110 it counts as stage 3. Readings below 159/99 have a pulse pressure above 60 mmHg — a wide gap that is common after 60 and worth mentioning to your doctor.
Hypertension stage 1 159/40 to 159/99
- 159/40 ↓
- 159/41 ↓
- 159/42 ↓
- 159/43 ↓
- 159/44 ↓
- 159/45 ↓
- 159/46 ↓
- 159/47 ↓
- 159/48 ↓
- 159/49 ↓
- 159/50
- 159/51
- 159/52
- 159/53
- 159/54
- 159/55
- 159/56
- 159/57
- 159/58
- 159/59
- 159/60
- 159/61
- 159/62
- 159/63
- 159/64
- 159/65
- 159/66
- 159/67
- 159/68
- 159/69
- 159/70
- 159/71
- 159/72
- 159/73
- 159/74
- 159/75
- 159/76
- 159/77
- 159/78
- 159/79
- 159/80
- 159/81
- 159/82
- 159/83
- 159/84
- 159/85
- 159/86
- 159/87
- 159/88
- 159/89
- 159/90
- 159/91
- 159/92
- 159/93
- 159/94
- 159/95
- 159/96
- 159/97
- 159/98
- 159/99
↓ = the lower number is below 50: these readings count as stage 1 by the upper number, but the low lower number needs checking — see each page.
Hypertension stage 2 159/100 to 159/109
Hypertension stage 3 159/110 to 159/123
What to do with a reading of 159 over …
Measure at home for 7 days, morning and evening, and take the average to your doctor. A home average of 135/85 or more confirms high blood pressure. From 159/110 the lower number makes it stage 3: sit quietly for 5 minutes and measure again; if it stays at 110 or higher, contact a doctor the same day, and call 911 (US) or your local emergency number with chest pain, shortness of breath, back pain, numbness or weakness, vision or speech problems, confusion or a severe headache. A lower number below 50 (from 159/49 down) is clearly low: measure again, and if it is confirmed or you feel dizzy, faint or confused, contact a doctor the same day. Keep your readings in a free blood pressure log and read how to measure correctly.
Sources: ESH 2023 guideline · AHA/ACC 2025 guideline.