Nighttime blood pressure should dip 10 to 20%; spiking instead usually traces to sleep apnea, salt, late-day stimulants, stress, or kidney issues, and it predicts cardiovascular risk better than daytime readings.
Obstructive sleep apnea is the leading driver: every breathing pause fires a pressure surge, all night long. High salt intake shows up at night too, since fluid redistributes when you lie flat. Evening alcohol, late decongestants or stimulants, stress, shift work, and kidney disease are the other usual suspects. Patterns have names: a normal dipper falls 10 to 20% overnight, a nondipper barely falls, and a riser actually climbs, with risers carrying the highest risk. The only way to know your pattern is measurement: 24-hour ambulatory monitoring or consistent bedtime and morning home readings. Mention snoring, witnessed pauses in breathing, and unrefreshing sleep explicitly to your clinician, because nocturnal hypertension is often a sleep apnea diagnosis waiting to be made. Treatment can include a sleep study, salt restriction, and retiming medication so it covers the night.
What to do
Common questions
Why does my blood pressure spike at night?
Blood pressure is supposed to fall 10 to 20% during sleep, a pattern called dipping. When yours spikes at night instead, or simply fails to dip, something is usually driving it. The biggest culprit is obstructive sleep apnea: each breathing pause triggers a pressure surge, so untreated apnea produces repeated nighttime spikes and is strongly linked to nocturnal hypertension. Other drivers: high salt intake (salt-sensitive people hold fluid that redistributes when lying down), stress and poor sleep, evening alcohol, stimulant or decongestant medications taken late, kidney problems, and shift work that scrambles the body clock. Why it matters more than you might think: research on ambulatory monitoring shows nighttime pressure predicts heart attack, stroke, and organ damage better than daytime readings, and a "riser" pattern (pressure climbing overnight) is the riskiest profile. The way to find your real nighttime pattern is 24-hour ambulatory monitoring, a cuff you wear for a day and night, or validated home readings taken at bedtime and on waking. If your nights run high, tell your clinician and specifically mention snoring, witnessed breathing pauses, or waking unrefreshed, because a sleep study may be the actual answer. Medication timing sometimes gets adjusted so coverage peaks overnight.