When the Seasons Change: How to Tell the Difference Between Allergies and Illness

Allergies: Nasal discharge usually has a watery and clear consistency. You may notice it gets worse when you are outside, near common allergens like fresh cut grass, or in a room with pets or dust. Nasal discharge will likely continue to linger if the allergen is present, which can make allergy season feel as if it is never ending. 

Respiratory Illness: Nasal discharge will often start out clear and watery on the first day or two, which makes it easy to confuse with allergies. As the illness progresses, it will likely thicken and turn a yellow or green color. This is a sign that your body is actively fighting a virus or infection, not allergies. 

Allergies: Sneezing caused by allergies can be frequent, repetitive and relentless. It often occurs one after another with no end in sight. This is your body's natural attempt at removing the allergen from the nasal passage. You may notice sneezing spells start almost immediately upon entering a space with a known trigger. 

Respiratory Illness: Sneezing can certainly accompany a cold or the flu, but it is typically not as frequent or intense as it is with allergies. Instead, it more commonly appears with other symptoms such as a sore throat, body aches or fatigue rather than appearing on its own. 

Allergies: Itchiness, particularly around the eyes, is a strong indication that there is irritation due to allergies rather than illness. If your eyes are red, watery or swollen, paired with an itchy nose that leads to uncontrollable sneezing, this can be a sign of allergies. Likely, histamine, a chemical that your body releases when it detects an allergen, is at work and causing this irritation. 

Respiratory Illness: Itchy eyes and an itchy nose are not usually symptoms of a cold or flu. A scratchy, sore throat is a possibility when you are sick, but this is usually more of a painful sensation rather than an itch. 

Allergies: Allergies do not cause a fever. Regardless of the severity of the other symptoms, a fever is not something that generally occurs. When experiencing a fever along with other symptoms, it is likely a virus or other issue is causing your temperature to spike. 

Respiratory Illness: Fever is one of the clearest symptoms that can help distinguish between allergies and respiratory illnesses. A cold may cause a low-grade fever, while the flu and COVID-19 are known for a sudden onset of high-grade fever, likely paired with chills and sweating. Either way, a fever is your body's natural defense mechanism working to fight off a virus or infection.  

Allergies: While allergies may not cause the same level of body aches and pain that come with the flu, they can still leave you feeling drained. The ongoing symptoms can cause exhaustion due to the extra effort your body is expending fighting off the allergy. Allergies can also cause brain fog during peak season, which can be just as disruptive to daily life as feeling physically ill.   

Respiratory Illness: Body aches are one of the most unmistakable symptoms of the flu, COVID-19 and a common cold. A cold seems to cause less pain while the flu may bring severe body aches, including in the muscles, the joints and even your skin. This is due to the cytokines, or the inflammatory response, that your body is using to fight the infection. 

Allergies: One of the most telling aspects of having seasonal allergies is that they are predictable. If you find yourself feeling the same way every spring when the trees bloom or every time you visit a friend with a cat, that pattern is a pretty strong indicator of allergies. Symptoms can go on for weeks or even months if the allergen is in the environment. For example, symptoms will  tend to improve when you are inside with all the windows closed, or after a hard rain has washed away spring pollen. Paying attention to how different environments or environmental changes worsen or help your symptoms can help you determine if you’re suffering from allergies. 

Respiratory Illness: Colds and the flu tend to follow a more predictable timeline. A cold will generally run its course within seven to ten days, often starting with a scratchy throat, followed by congestion and a runny nose, and then gradually improve from there. The flu typically hits harder and faster, but with plenty of rest, symptoms usually resolve within one to two weeks. If your symptoms have lingered well beyond a two week window and you have not experienced a fever or the typical progression of illness, it may be worth considering whether allergies are the culprit. 

Allergies: Allergy symptoms can appear almost immediately, sometimes in a matter of minutes after exposure to the allergen. This happens because your immune system identifies the allergen and immediately triggers a histamine response. 

Respiratory Illness: Unlike allergies, the symptoms of a virus tend to show up slowly over time. After being exposed to a virus, it usually takes one to three days for symptoms to appear for a cold, and one to four days for flu symptoms to set in. This gradual onset can make it difficult to pinpoint exactly when or where you were exposed to the virus. You may also notice with respiratory illness that your symptoms will typically peak over the first few days before slowly improving. 

Your symptoms last longer than 10 days without improvement

You develop a fever above 103°F or a fever that persists for more than three days 

You experience difficulty breathing or chest tightness 

Over-the-counter medications are not providing adequate relief 

Your symptoms are interfering with your daily life, work or sleep 

You are unsure whether you are dealing with allergies, a cold or something more serious