The dietary evidence is strong. The DASH trial showed that a diet rich in fruit, vegetables and low-fat dairy foods lowers blood pressure (Appel et al., 1997), and its successor showed a further fall with reduced sodium (Sacks et al., 2001). Weight loss, physical activity and moderation of alcohol are likewise supported by trials and endorsed for primary prevention (Whelton et al., 2002). Fasting stands on weaker ground. Uncontrolled series from a residential centre have described substantial falls in pressure during medically supervised water-only fasting in people with hypertension and with borderline values (Goldhamer et al., 2001; Goldhamer et al., 2002), and a large observational study of periodic fasting reported falls in blood pressure with few serious adverse events (Wilhelmi de Toledo et al., 2019). Physiological reasons to expect an effect exist, including sodium loss and weight loss (de Cabo and Mattson, 2019). None of these studies had a control group, all were accompanied by a low-salt plant-based diet, and how long the falls last after normal eating resumes is uncertain.

For hydrotherapy the evidence is thinner still. Warm immersion dilates skin vessels and lowers pressure for a time, while cold application raises it acutely through sympathetic activation. A review of the physiological literature lists a range of cardiovascular effects of water treatments and few adequately controlled trials in hypertension (Mooventhan and Nivethitha, 2014). Whether a course of baths or packs lowers resting pressure in a lasting way is not established.

Blood pressure varies from minute to minute and is raised in many people by the clinic itself. Guidelines therefore ask for validated automatic upper-arm devices, a cuff of the correct size, a seated rest of five minutes, and the average of repeated readings (Stergiou et al., 2021). Home measurement over seven days, with duplicate readings each morning and evening and the first day discarded, gives a more reproducible estimate than office readings and is recommended for confirming the diagnosis (Parati et al., 2008). A case of early hypertension that rests on two or three clinic readings has not established its own starting point.

Case reports have a recognised place. They generate hypotheses, describe how an intervention is delivered and record harms (Vandenbroucke, 2001). The CARE guidelines set out thirteen items that a report should contain, among them a timeline, a full description of the intervention, follow-up and outcomes, and the patient's own perspective (Gagnier et al., 2014; Riley et al., 2017). What a case report cannot do is estimate an effect. Its value lies in the completeness and honesty of the record.

The first task is to confirm that the person has early, uncomplicated hypertension and that fasting is safe for them. A medical assessment records history, current medicines, cardiovascular risk factors and evidence of organ damage, and excludes secondary causes as far as the guidelines require. Published consensus on fasting therapy lists the conditions in which it is contraindicated or needs particular caution, such as pregnancy, eating disorders, advanced kidney or liver disease and frailty (Wilhelmi de Toledo et al., 2013). People taking antihypertensive or glucose-lowering medicines need a physician to manage those medicines throughout. Baseline pressure is then established by a week of home readings to the standard schedule, together with weight, waist circumference and a brief record of usual diet.

Before the intervention the report fixes what will be done and what will be measured. The planned hydrotherapy is written out by type, water temperature, duration, body region and frequency, and the planned dietary regime by its composition, energy content where known, fluid and salt intake, and intended length. Any change in medication is recorded with its date and reason. Written informed consent is obtained for treatment and for publication. Stating the plan in advance is what later allows a reader to see whether the report describes what was intended or only what turned out well.

During the programme, blood pressure and pulse are taken at the same times each day with the same device, seated and after rest, and also standing, since a postural fall is a known hazard of fasting. Weight is recorded daily. Every hydrotherapy session actually given is logged against the plan. Symptoms are asked about with a fixed list that includes dizziness, headache, weakness, palpitations and sleep disturbance, and laboratory tests are ordered when the clinician judges them necessary. The record states in advance the findings that would stop the fast, and the guideline thresholds at which pressure calls for urgent medical referral.

The return to food is part of the intervention and is documented in the same detail: what was eaten on each day, the salt content of the diet as far as it can be judged, and weight. Home readings resume on the standard schedule once the person is back in ordinary surroundings.

A fall in pressure on the last day of a residential programme is the least informative number in the case. The protocol asks for a week of home readings at fixed points after discharge, for example at one, three and six months, with weight, current diet, activity and medication at each. If follow-up is lost, the report says so. The patient's own account of the experience and of what they have continued to do is included, as CARE requires.