Study design: Prospective, multicentric, randomized, comparative study Study duration: between 4 and 19 weeks depending on the study group. Population: minimum 35 hypertensives (stage 1 or stage 2) participants divided into 3 groups depending on hypertension criteria. GROUP 1 = untreated hypertensives, stage 1 or stage 2; GROUP 2 = hypertensives, stage 1, who are taking antihypertensive monotherapy; GROUP 3 = hypertensives, stage 1 or stage 2, who are taking antihypertensive treatment that doesn't allow them to have controlled blood pressure.

Device Under Test (DUT): Aktiia device Reference: HBPM (Aktiia cuff) Periods of treatment: For GROUPS 1 and 2, 2 weeks of treatment for each antihypertensive medication followed by a washout period of 2 weeks (3 antihypertensive medications in total with a fixed dose; medication intake order is randomly assigned). For GROUP 3, an individualized new antihypertensive medication will be prescribed during the consultation with the investigator that will be administered for 3 weeks.

This study with N = 35 participants minimum, over 2 to 6 visits, depending on the study group, has been designed to compare Aktiia device systolic and diastolic blood pressure measurements against HBPM reference measurements in participants taking 3 successive BP-lowering medications during 2 weeks per treatment for GROUPS 1 and 2, while GROUP 3 will receive, during 3 weeks, an individualized medication decided by the investigator. For GROUPS 1 and 2, periods of treatment are followed by 2 weeks of washout.

Study participants are: For GROUP 1, hypertensive Stage 1 (SBP 140-159 mmHg or DBP 90-99 mmHg) or hypertensive Stage 2 (SBP 160-179 mmHg or DBP 100-109 mmHg) that are naive of antihypertensive treatments at the inclusion in the study. For GROUP 2, hypertensives Stage 1 (SBP 140-159 mmHg or DBP 90-99 mmHg) with no other cardiovascular risk factors who are taking an antihypertensive monotherapy, for whom previous treatment will be stopped at the study inclusion and will be resumed for the last 4 weeks of the study participation. For GROUP 3, uncontrolled hypertensive Stage 1 (SBP 140-159 mmHg or DBP 90-99 mmHg) or hypertensive Stage 2 (SBP 160-179 mmHg or DBP 100-109 mmHg) who are taking antihypertensive treatment that doesn't allow them to have controlled blood pressure.

Study participants are asked to:

Wear the Aktiia bracelet continuously every day for 4 to 19 weeks in total, depending on the study group, Initialize their bracelet with the Aktiia cuff at different time points, Measure their blood pressure with an HBPM (Aktiia cuff) twice per day, Take their BP-lowering medications during the treatment periods, Complete 2 to 3 different surveys, depending on the study group, to give their feedback on Aktiia product use compared to HBPM.

Inclusion Criteria:

1. Adult subjects aged 21 to 85 years old
2. Subjects that can read and speak French
3. Subjects that own a smart phone that uses either the iOS or Android operating system
4. Hypertensive Stage 1 (SBP 140-159 mmHg or DBP 90-99 mmHg) or Hypertensive Stage 2 (SBP 160-179 mmHg or DBP 100-109 mmHg) or for subjects aged > 65yo SBP ≥160 mmHg,
5. Naive of antihypertensive drugs at the inclusion in the study (no antihypertensive drugs taken in the last 3 months before Visit 1) and during the conduct of the study apart from the study drugs
6. Subjects agreeing to attend all 4 on-site visits and follow study procedures
7. Subjects that have signed the informed consent form

Exclusion Criteria:

1. Subjects have contraindications to the study drugs

2. Subjects with Hypertension Stage 3 (SBP/DBP >180/110 mmHg)

3. Subjects with orthostatic hypotension (a 20 mmHg decrease in systolic BP, or 10 mmHg decrease in diastolic BP when measured in the standing position after a 1-minute waiting period)

4. Subjects who are likely to be unable to perform the HBPM required for the study within the designated time frame (7 to 11

   a.m. and 4 to 9 p.m.).

5. Subjects having medical interventions or taking treatments during the study that could have an impact on their BP

6. For GROUPS 1 and 2 only: Subjects with target organ damage (left ventricular hypertrophy observed on ECG, and/ or, albumin/creatinine ratio in urine ≥3.5 mg/mmol)

7. Subjects with tachycardia (heart rate at rest > 120bpm)

8. Subjects with atrial fibrillation

9. Cardio myopathy (FE<40%)

10. Severe valvular disease

11. Implanted devices such as a pacemaker or defibrillator

12. Subjects with diabetes

13. Subjects with renal dysfunctions (eGFR < 45mL/min/1.73 m2 for patients between 21-85 yo)

14. Subjects with hyper-/hypothyroidism

15. Subjects with pheochromocytoma

16. Subjects with Raynaud's disease

17. Subjects with an arteriovenous fistula

18. Women in known pregnancy

19. Subjects with trembling and shivering

20. Subjects with lymphoedema

21. Low or elevated potassium level: threshold ≤3.5 mmol/L or ≥4.8 mmol/L

22. Presence of an intravascular device

23. Subjects with exfoliative skin diseases

24. Subjects with arm paralysis

25. Subjects with arm amputation

26. Subjects with upper arm circumference < 22cm or > 42cm

27. Subjects with wrist circumference > 23cm

28. Subjects with non-standard circadian rhythm, including shift workers and night workers

29. Subjects who have received a mastectomy.