A blocked nose, sneezing, or a persistent runny nose shortly after leaving the water is a common physiological response known as swimmer’s rhinitis. This temporary nasal congestion affects many swimmers and can manifest immediately or several hours after a session. While often attributed simply to water going up the nose, the congestion is caused by a combination of chemical irritation and physical disruption within the nasal passages. Understanding these specific mechanisms helps in finding effective relief.
How Pool Chemicals Irritate Nasal Passages
The primary cause of post-swim congestion in pools is not the chlorine disinfectant itself, but rather the chemical byproducts it forms. Chlorine reacts with organic matter introduced by swimmers, such as sweat, urine, and skin cells, creating compounds called chloramines. These volatile compounds off-gas from the water and are potent irritants to the delicate mucous membranes lining the nose and respiratory tract.
When inhaled, chloramines trigger a localized inflammatory response, which is a type of irritant rhinitis. The body’s defense mechanism causes the tissues inside the nose to swell, a process called mucosal edema, and increases mucus production to flush out the chemical irritant. This swelling narrows the nasal passages, resulting in the stuffy feeling. Poor ventilation in indoor pools can exacerbate this issue, as it allows airborne chloramines to accumulate above the water, increasing exposure.
The Role of Water Pressure and Mucus Buildup
Congestion can occur even in natural water bodies like lakes or oceans, indicating a separate, physical mechanism is at play. When water rushes into the nasal cavity, especially while diving or flipping, the sudden change in hydrostatic pressure can force water deep into the sinus passages. This mechanical intrusion disrupts the natural balance of the sinuses and washes away the mucosal blanket, a thin layer of protective mucus that traps foreign particles.
The sinuses respond to this physical disruption and the presence of non-sterile water by initiating a protective reaction. The ciliated cells that normally sweep mucus out of the sinuses become impaired, and the body ramps up mucus production to re-establish the protective layer. This excess, often thicker mucus, combined with the inflammation caused by the pressure change and the irritation from any contaminants in the water, leads to temporary blockage and the sensation of fullness or pressure.
Strategies for Prevention and Relief
Preventing water from entering the nasal cavity is the most direct way to avoid post-swim congestion. Swimmers can use a nose clip, which physically seals the nostrils and prevents exposure to both chemical irritants and the disruptive hydrostatic pressure changes. Alternatively, learning to exhale gently through the nose while underwater can create a slight positive pressure, which helps to keep water out of the nasal passages.
For immediate relief after swimming, gentle nasal rinsing is a highly effective strategy. Using a sterile saline solution or a Neti pot helps to physically flush out any residual chloramines, bacteria, or excess mucus that has accumulated in the nasal and sinus passages. This rinsing action helps to calm the irritated mucous membranes and reduce swelling. If congestion persists, over-the-counter options like antihistamines or short-term decongestant nasal sprays can be used, though sprays should be limited to a few days to avoid the risk of rebound congestion.