A blood pressure log is more useful than any single reading, because it shows your doctor what happens in everyday life instead of only during a short clinic visit. Record the date, the time, both numbers, your pulse if your monitor shows it, and short notes such as "after walking", "missed my tablet" or "slept badly". Writing the context next to the number helps explain readings that look surprising.
When you review the log, look for patterns instead of single peaks. Are morning readings higher than evening ones? Do numbers rise on days when doses are missed, or after salty meals? A cluster of high readings across several days matters far more than one isolated number after a stressful day. Many guidelines treat an average of home readings at or above 130/80 as high, but your own target may be different, so ask your doctor what yours should be.
Before an appointment, bring the log, your monitor and your current medicine list. Share the pattern in simple words: "most mornings are around this level, and evenings are lower." Ask whether your numbers show the treatment is working and whether any change is needed. Do not adjust your dose yourself based on the log. Seek urgent care for a very high reading, usually 180/120 or above, especially with chest pain, severe headache, confusion, weakness or trouble breathing.