My BP is usually around 145/153 over 80/85 (and I'm taking BP medication for that) but sometimes it spikes to 190-98 over 90/98 and I feel nauseated and faint. It's happened before and I thought it was caused by low BP. My son loaned a BP meter and the next time it happened I began collecting the readings. Could the symptoms be caused by high BP or is it something else? The spikes may last upwards of 20 to 40 minutes and many of the times I'm not active at all; watching TV or responding to e-mails etc.