Common Cold

Although “the common cold” is typically treated like a single condition, it’s actually a generic term for mild upper respiratory tract infections caused by viruses (such as rhinovirus, respiratory syncytial virus, human metapneumovirus, and non-COVID coronavirus, to name a few). It’s one of the most common illnesses in the world — adults will get 2–3 colds each year, on average, and children can get many more.^{[1] [2]}

One of the key differences between colds and the flu is symptom severity. Colds tend to be mild; the flu is often more severe, and the latter may not involve upper respiratory symptoms at all.^[3]

• Fever (common in children; less common in adults)
• Runny or stuffy nose
• Green or yellow nasal discharge
• Sore throat
• Coughing/sneezing
• Fatigue
• Muscle aches
• Headache

Colds are frequently self-diagnosed. In a clinical setting, they are primarily diagnosed based on a clinician’s impression of their patient’s symptoms. Typically, a “cold” is distinguished from the flu based on how quickly the symptoms come on and how severe they are. Historically, it’s been rare for clinicians to perform diagnostic tests, but post-COVID-19, it’s becoming more common.

There are no cures for the common cold; treatments are focused on managing symptoms until the cold ultimately resolves on its own. For this purpose, people may use:

• Anti-inflammatory medications such as non-steroidal anti-inflammatory medications (NSAIDs) or acetaminophen.^[4][5]
• Decongestants such as ephedrine and pseudoephedrine.^[6]

Again, no supplements can cure the common cold. However, zinc seems to quite reliably reduce symptom duration. Echinacea, Pelargonium sidoides, and garlic may also be helpful for reducing symptom duration, but there’s not enough research to know definitively.

Diet is mainly related to the common cold through immunity. Diets that are sufficient in energy, micronutrients, and macronutrients are important for maintaining a robust immune system, which will help reduce the risk and severity of common cold infections.^[7] Flavonoids (plant compounds that have antioxidant and immunomodulatory properties; found in especially high quantities in tea, chocolate, capers, and oregano)^[8] may be a noteworthy nutrient for this purpose.^[9]

Saline nasal and sinus irrigation (using devices like a neti pot or a nebulizer) may improve cold symptoms. However, it’s very important to only use water that has been filtered, sterilized, or otherwise treated for such uses — serious infections can occur otherwise.^[10]

Some trials report that meditation and exercise may reduce the risk and severity of the common cold.^[11][12]

The common cold is caused by a large number of viruses. Over 200 viruses have been identified as causing colds, many of which are classified as rhinoviruses. These viruses are constantly present in the environment, and infection can occur from physical contact with infected people or surfaces, breathing in small-particle aerosols containing virus in the air, or being directly hit by large-particle aerosols from a person coughing or sneezing.^[13][1] Infections are most common in the winter and spring and during rainy seasons in tropical areas.^[13]