Coronary Heart Disease And Hydration

What is Coronary Heart Disease?

Cardiovascular disease (CVD) is an umbrella term for pathologies that affect the heart and blood vessels, including coronary heart disease (CHD) and strokes. CVD’s burden cannot be understated; it is the primary cause of death worldwide, constituting over 30% of global deaths in 2019.1  

CVD does not have one main risk factor, with a range of genetic markers and environmental factors contributing to the increased likelihood of disease onset. This complex, multifactorial risk profile makes it hard to prevent, but there is a multitude of lifestyle changes you can make to reduce your individual risk. Classic measures to reduce CVD risk include drastic lifestyle changes like altering dietary and exercise behaviours, whilst maintaining hydration is another often overlooked way to mitigate relative CVD susceptibility. Patients can take their health into their own hands by just turning on the tap. 

Staying Hydrated Helps Keep the Heart Working Well

Drinking enough water to stay hydrated seems like an easy task, water is everywhere, after all, however, over half of the population does not drink enough water, their daily intake being less than the recommended 8 glasses a day. Staying hydrated is a valid action often ignored in the search for a healthier lifestyle but is important for the proper functioning of the body as a whole. 

In the context of CVD, optimal hydration means that the heart can pump blood around the body more efficiently reducing the strain on the heart and vessels. This is because when someone has not consumed enough water their blood volume is relatively low. This means that the heart has to pump harder and faster to compensate for the reduced volume so that each bodily tissue still receives enough blood. Eventually, this extra strain will damage the heart and blood vessels causing serious internal injury and CVD. 

When you are dehydrated, the brain releases vasopressin, a hormone that acts on the heart and kidneys.This causes constriction of blood vessels and an increase in arterial blood pressure to compensate for the reduced blood volume. If blood pressure is elevated, so is the risk of wear and tear to the vessels carrying the blood. If these vessel walls are damaged, atherosclerotic plaques may form which contribute to the vessel blockages that cause strokes and heart attacks. 

If blood volume is low, it means that its viscosity will increase (blood thickness) this reduces the efficiency of blood traveling through microvessels of the body (capillaries) to reach cells of the tissues that need it.Reduced circulatory efficiency will cause reduced muscle recovery and long-term damage.

Dehydration Increases the Long-Term Risk of Coronary Heart Disease

Chronic hypohydration (low fluid intake) elevates the long-term risk of developing CVD, especially coronary heart disease. This is because when water levels in the body are low, blood sodium (salt) concentrations are high. 

When the body is dehydrated, vasopressin acts to increase sodium reabsorption back into the bloodstream within the kidneys and causes the body to crave salty foods. High sodium concentration in the bloodstream directly affects heart muscle by altering the structural makeup of muscle fibres within heart muscle cells, limiting their contractile capacity. This means the heart will not pump as effectively. 

Furthermore, high sodium also reduces the activation of these heart muscle cells, limiting the contractile force of the heart walls.5 In response to the prolonged hits to the heart's strength from chronically increased sodium in the bloodstream, the heart must work harder to compensate for this, increasing heart rate and blood pressure. This generates a stressful environment within the circulatory system, causing heart failure and vascular damage. 

When to Contact a Doctor

This article hopefully has given you increased awareness surrounding CVD and its environmental risk factors. Its grim statistics are not intended to scare but to inform and help you keep an eye out for worrying symptoms linked to CVD. Like a lot of ailments, early detection is vital to the success of treatment. 

To be more vigilant toward CVD, it is beneficial to attend regular health check-ups and to contact urgent medical help if experiencing CVD-related symptoms. These especially include (but are not limited to) the incidence of sudden and intense chest pains that run down the left arm and sudden dizziness (read more about disease-specific symptoms here).  


It is clear that hypohydration is a threat to health, especially as a risk factor for CVD. It must be noted that the positive effect of hydration on heart disease is only observed when consuming water and other non-alcoholic, sugar-free beverages. Research has shown that the use of sugary drinks and alcohol has the opposite effect and increases the cardiovascular burden on the patient. It's therefore recommended that we all try and boost our water intake to at least 2 litres per day to contribute to a healthy lifestyle and help avoid pathologies such as CVD. 

Drinking enough water is only one factor in a healthy, preventative lifestyle, it is also important to be mindful of the benefits of a strong sleep pattern, a healthy, varied diet, sufficient exercise and nurturing mental health on reducing CVD risk. Following these recommendations will put you in the best position possible for the prevention of CVD.


  1. Bhatnagar P, Wickramasinghe K, Williams J, Rayner M, Townsend N. The epidemiology of cardiovascular disease in the UK 2014. Heart. 2015 Aug 1;101(15):1182-9.
  2. Stookey JD. Analysis of 2009–2012 nutrition health and examination survey (NHANES) data to estimate the median water intake associated with meeting hydration criteria for individuals aged 12–80 years in the US population. Nutrients. 2019 Mar 18;11(3):657.
  3. Bichet DG. Vasopressin at central levels and consequences of dehydration. Annals of Nutrition and Metabolism. 2016;68(Suppl. 2):19-23.
  4. Dintenfass L. The cause of death: blood hyperviscosity?. Journal of the Royal Society of Medicine. 1987 Aug;80(8):536.
  5. Patel Y, Joseph J. Sodium intake and heart failure. International journal of molecular sciences. 2020 Dec 13;21(24):9474.
  6. Chan J, Knutsen SF, Blix GG, Lee JW, Fraser GE. Water, other fluids, and fatal coronary heart disease: the Adventist Health Study. American journal of epidemiology. 2002 May 1;155(9):827-33.

Frankie Perrett

MSc Molecular Medicine and BSc Biological Sciences – University of East Anglia, Norwich

Frankie works in an NHS Hospital Pathology laboratory so has acquired excellent insight into many different diseases and their mechanisms of action.

Frankie’s Master’s course focused on key areas of biomedicine, centring around patient-first learning. In her degree, she specialised in Lung adenocarcinoma and its mechanisms of cell communication. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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