Experiencing a runny or stuffy nose while taking Fildena 100 mg (sildenafil citrate) is a potential side effect that some individuals may encounter. Here's why this side effect might occur: Vasodilation: Sildenafil citrate, the active ingredient in Fildena 100 mg, works by inhibiting the enzyme phosphodiesterase type 5 (PDE5), leading to vasodilation (widening of blood vessels) and increased blood flow, primarily to the penis. However, sildenafil citrate can also cause vasodilation in other parts of the body, including the nasal passages. This vasodilation may result in a sensation of nasal congestion or a runny nose. Increased Blood Flow: The increased blood flow caused by sildenafil citrate can lead to engorgement of blood vessels in the nasal mucosa, contributing to nasal congestion or a runny nose. This effect is similar to the congestion that occurs during episodes of nasal inflammation, such as during a cold or allergy. Side Effect: Nasal congestion or a runny nose is a known side effect of Fildena 100mg and other medications in the same class (phosphodiesterase type 5 inhibitors). While not everyone will experience this side effect, it can occur in some individuals as a result of the medication's mechanism of action. Individual Sensitivity: Some individuals may be more sensitive to the side effects of sildenafil citrate, including nasal congestion or a runny nose. Factors such as individual physiology, underlying health conditions, and concurrent medication use can influence the likelihood and severity of side effects. Temporary Effects: Nasal congestion or a runny nose experienced while taking Fildena 100 mg is usually temporary and should resolve once the medication is metabolized and eliminated from the body. If nasal symptoms persist or become bothersome, it's essential to discuss them with a healthcare provider. It's important to note that while nasal congestion or a runny nose can be a side effect of sildenafil citrate, it's generally mild and temporary for most individuals. If you experience persistent or severe nasal symptoms while taking Fildena 100 mg, or if you have any concerns about side effects, consult your healthcare provider for further evaluation and guidance. They can provide personalized advice and recommendations based on your individual health status and needs.