Starting a new blood pressure medicine: what changes in the first weeks, what to record and why your doctor wants the numbers

Starting a new blood pressure medicine can take time to settle in. Some people notice new feelings in the early days, and that is common. You can record your readings, when you took the tablet and how you felt, on paper or in the blood pressure diary in Sam, which gathers it into a doctor report as a PDF for your next appointment. Your doctor sets the plan.

This text is for you if a doctor has already prescribed a blood pressure medicine. It does not tell you what dose to take. That belongs to your doctor.

What usually happens in the first weeks?

Blood Pressure UK says side effects can appear when you first start a medicine or a higher dose. As your body gets used to it, they often improve or go away. Finding the medicine or combination that suits you can take a little trial and error.

Your doctor will usually want to see you again fairly soon after you start. This checks how well the medicine works and whether any side effects bother you. The record of your first weeks is the best basis for that conversation.

One common early sign is feeling faint or dizzy when you stand up, especially at night. Blood Pressure UK calls this postural hypotension and says it can happen with any blood pressure medicine. Your practice can tell you whether it matters for you.

What you record while you settle in

For your check-up, your doctor needs a record, not your judgement. A diary with three building blocks helps your doctor. Blood Pressure UK suggests recording your readings with date and time, and when you took your medication. Adding how you felt shows side effects:

• Your readings, regularly, with date and time.
• When you took your tablet.
• How you felt, such as dizziness, tiredness or headache.

Record the values you do not like as well as the ones that please you, plus the ordinary days. Blood Pressure UK also suggests noting anything that might have affected your pressure. A full picture beats a selected one.

You do not judge the numbers yourself. You bring them to the appointment. In Sam you enter readings with pulse and arm, and you can note how you feel in the symptom diary.

Why the timing of your dose belongs in the record

When you took your tablet is one of the facts your practice needs. A record shows which days you took the medicine and what your readings were on those days. That tells your doctor more than memory at the appointment.

Never stop a prescribed medicine on your own, and do not change the dose yourself. Blood Pressure UK and the British Heart Foundation both say to talk to a healthcare professional first. Your medication list in Sam keeps note of what you took over the weeks, as the basis for the talk.

For a missed dose, Blood Pressure UK says not to take two tablets together. Check your leaflet or ask your pharmacist.

What the record becomes at your check-up

With a steady record, you and your practice can talk about how the medicine works, whether symptoms came up and whether the dose suits you. If something needs to change, your doctor decides it, often step by step over weeks. Blood Pressure UK describes starting low and raising the dose gradually.

Bring the record to every follow-up. NICE says adults with high blood pressure get an annual review of their care, and daily home numbers help that conversation. See living with high blood pressure and daily readings for how home values add to the discussion, and newly diagnosed high blood pressure for the wider picture. Our doctor visit checklist has a general list of what to bring.

When to get urgent medical help

A very high reading is not a topic for a diary, and a log does not replace an emergency call. NICE calls a clinic reading of 180/120 or higher severe hypertension. It needs same-day specialist assessment when it comes with life-threatening symptoms. Those include new confusion, chest pain or signs that the heart is struggling. If a home reading is above 180/120, wait 5 minutes and test again, as the US National Heart, Lung, and Blood Institute advises. If it is still high, contact your doctor right away. With a sudden severe headache, difficulty breathing, sudden severe pain in the chest, abdomen or back, numbness or weakness, a sudden change in vision, or problems talking, call your local emergency number.

Swelling of the face, lips, tongue or throat can follow a dose of an ACE inhibitor. The British Heart Foundation lists swelling around the mouth, face or throat among the side effects. The NHS page on ramipril says to call 999 or go to A&E for swelling of the lips, tongue and face. If your face, lips, tongue or throat swell, call your local emergency number straight away.

If you faint after a dose, the NHS says fainting is not usually serious but you should see a GP. The NHS also says to call an emergency number if the person cannot be woken within a minute, has hurt themselves, or has chest pain or a pounding, fluttering heartbeat. Use your local emergency number (112 in the EU, 999 in the UK, 911 in the US). This text does not replace a medical assessment.

Record the first weeks in Sam and take them to your appointment

You arrive at your check-up with a record of readings, doses and how you felt, instead of trying to piece the weeks together from memory.

• Instead of a paper log: you enter each reading with date, pulse and arm in the high blood pressure program, and readings your monitor saved to Apple Health come in for the last 180 days.
• Instead of memory: the medication list records what you took, and reminders help on scheduled days.
• Instead of loose notes: the doctor report (PDF) puts readings, doses and symptoms together for the appointment.

The program starts after a doctor has diagnosed high blood pressure. Sam gives no dose advice and does not measure blood pressure.

Try Sam for free

Sam is a wellness companion, not a medical device. The app does not diagnose, treat, cure or prevent any condition or health state. Always consult qualified professionals for medical decisions.

Related reading

• Living with high blood pressure and daily readings
• High blood pressure diagnosis: what now?
• Doctor visit checklist for a chronic condition

Sources

Updated: October 2026

• NHS: High blood pressure (hypertension) (last reviewed 19 July 2024)
• Blood Pressure UK: Medications for high blood pressure
• Blood Pressure UK: How to measure your blood pressure at home
• British Heart Foundation: ACE inhibitors (published 27 March 2026)
• NICE: Hypertension in adults: diagnosis and management (NG136) (last updated 26 February 2026)
• NHS: Side effects of ramipril. Swelling of the lips, tongue and face (angioedema): call 999 or go to A&E.
• NHS: Fainting (last reviewed 17 August 2026)
• National Heart, Lung, and Blood Institute (NIH): High blood pressure symptoms (updated 25 April 2024). Above 180/120: wait 5 minutes, check again, call 9-1-1 with symptoms.