Blood Pressure 86 Over 40–85: Which Are OK?
With an upper value of 86, the answer depends on your lower number. Here are all readings, sorted by what they mean.
On its own, a systolic (upper) value of 86 mmHg is Low blood pressure by the international categories (2023 ESH guideline) and low under the 2025 AHA/ACC guideline. The worse of your two numbers decides the category, so a raised diastolic (lower) value moves a 86 reading up: from 86/80 it counts as normal, from 86/85 it counts as high normal.
Low blood pressure 86/40 to 86/71
High normal 86/85
What to do with a reading of 86 over …
Low. If you feel well, that is often harmless; with dizziness, light-headedness or fainting, talk to your doctor — especially after a change of medication. A lower number below 50 (from 86/49 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.