Respiratory Health and Hydration

If you are sick with a cold or flu, it is common for people to say ‘keep up with the fluids’ but have you ever questioned why this is and how keeping hydrated actually assists in maintaining good respiratory health? This article answers these questions and shows why it is important to stay hydrated to keep the airways clear and functioning well.

What is good respiratory health?

The respiratory system is a linked network of organs and tissues, including airways, blood vessels, lungs and the muscles that assist in our breathing.¹ This network works together to push oxygen around the body and clear off unwanted gasses such as carbon dioxide when we exhale. It is important to have a strong respiratory system to enable us to breathe, talk and smell sufficiently, deliver oxygen to cells in our body and protect our airways from dangerous substances and irritations.

A healthy respiratory system is demonstrated by breathing with ease and being able to take long deep breaths without struggle or interruption. To maintain good respiratory health you should avoid exposure to air pollutants including smoke, strong chemicals and cigarette smoke, eating a healthy diet including lots of water, exercising frequently and washing your hands regularly. ²

When our respiratory health is compromised we may suffer from coughing, shortness of breath, mucus production, wheezing, coughing up blood and chest pains. It is important to pay attention to these symptoms. If they persist, it could be an early sign of lung disease, including COPD, asthma or lung cancer. ³

Does hydration affect respiratory health?

Homeostasis is crucial to the functioning of all organ systems, including the lungs. Staying hydrated plays a large part in this, as fluids are essential to maintain a healthy respiratory system.⁴ One quarter of the daily water requirements for human beings are used up during respiration.⁵ A 70kg human needs approximately 2 900ml of water per day, meaning that approximately 725ml of this is lost during respiration. The amount of water required to cover the alveolar surface must remain constant in order for the respiratory system to work effectively. Staying hydrated also helps to thin the mucus lining across our airways and lungs, enabling good respiratory health.⁶ This is particularly important for those with COPD, as it makes it easier for the individual to cough up the excess mucus that may be causing breathing difficulties.

What does dehydration do to your lungs?

Mucus becomes too sticky

As mentioned, throughout our airways and lungs there is a mucus lining. When not enough liquids have been consumed this lining thickens and becomes sticky. This mucus barrier makes the lungs vulnerable to injury and makes you more susceptible to illnesses and allergies, as the airways cannot function as smoothly and efficiently.⁷ Conditions such as asthma, allergies and bronchitis can enhance the build up of mucus in the airways. Drinking liquids help thinning and loosen the mucus which can help decongest your respiratory system. Warm liquids in particular are especially effective.

Lung and bronchi linings become too dry

The lungs and bronchi are a key part of our respiratory system. The bronchi are the large air passages that lead from the trachea (windpipe) to the lungs.⁸ The lungs are remarkably resistant to pollutants in the environment, despite the continuous pathogens and toxic chemicals that we inhale. This is because the mucus lining traps the toxins and protects us by pushing the particles out of the lungs through coughing. ⁸ However, if the body is water deficient, the linings become too dry which can lead to infections and breathing problems. 

Triggered allergic reaction

Having an allergic reaction may not be something you associate as a causal effect of being dehydrated but the function of histamine means that it can happen. Histamine is stored in cells that line most tissues inside our bodies and has many different roles. One role is that it is a neurotransmitter, meaning that it regulates the flow of water throughout our bodies and ensures that our cells stay hydrated. ¹⁰ If we are dehydrated, histamine will try to redistribute water to ensure that the vital organs have enough water to function properly. If we are severely dehydrated, water may have to be taken from major regions. Chronic dehydration can mean that histamine is excessively produced and lead to symptoms that are mistaken for other disorders,^{6 7 8} such as asthma, headaches, acid reflux and chronic pain, otherwise known as an allergic reaction. ⁹

Conclusion

As you can see there are many ways that hydration plays a role in our respiratory health. This article has outlined the huge knock-on effects that can arise when dehydrated and the negative symptoms that can occur. If you have a respiratory infection or suffer from an illness such as COPD, you now know why it is indeed important to ‘keep up with the fluids’.