It’s easy to confuse allergy symptoms with those of a cold, especially when both share similar signs like a runny nose and sneezing. However, there are some key differences that can help you tell whether you’re dealing with allergies or something else.

Understanding Allergies vs. Colds

Allergies occur when your immune system reacts to harmless substances like pollen or dust, treating them as threats. This results in inflammation and the release of histamines, chemicals that can cause itchiness, swelling, and irritation. On the other hand, a cold is caused by a viral infection, and while your immune system is still activated, histamines aren’t the main players.

Because both conditions involve immune system responses, it’s not uncommon for symptoms to overlap, but subtle differences can help you figure out what’s going on.

What Does a Cold Look Like?

The common cold is a mild respiratory infection that typically resolves within a few days. While it can be uncomfortable, it doesn’t usually require medical attention unless symptoms become severe. Common cold symptoms include:

• Nasal stuffiness or runny nose
• Sneezing
• Sore throat
• Cough

Depending on the virus causing the cold, you may also experience:

• Sinus pressure
• Headache
• Fatigue
• Body aches
• Low-grade fever (though rare)

Cold vs. Allergies: Key Differences

While colds and allergies can both involve a runny nose, sneezing, and sinus congestion, there are notable differences:

• Fever: A cold may cause a low-grade fever, but allergies never do.
• Wheezing and Itchy Eyes: Allergies are more likely to cause wheezing and itchy, watery eyes, whereas these symptoms are uncommon with a cold.
• Skin Reactions: Allergies can lead to hives, rashes, or facial swelling, none of which are typical cold symptoms.
• Fatigue and Body Aches: Fatigue and body aches are common with a cold but are less frequent with allergies.

Here’s a quick comparison:

Symptom	Allergy	Cold
Runny Nose	Common	Common
Sneezing	Common	Common
Sore Throat	Possible	Common
Cough	Possible	Common
Sinus Pressure	Possible	Possible
Post-Nasal Drip	Common	Common
Headache	Possible	Possible
Fatigue	Common	Common
Body Aches	Uncommon	Possible
Wheezing	Possible	Uncommon
Watery/Itchy Eyes	Possible	Uncommon
Hives/Rashes	Possible	Rare
Facial Swelling	Possible	Rare
Stomach Upset	Possible	Rare
Fever	Never	Possible

Timing of Symptoms: When Do They Appear?

The way your symptoms show up can be a good indicator:

• Colds develop gradually over several days and usually resolve in about three days.
• Allergies start almost immediately after exposure to an allergen, and they last as long as you’re exposed.

Seasonal Considerations

While colds can happen any time of the year, they’re more common in colder months, particularly from December to February. Allergies, however, can be seasonal, depending on what you’re allergic to:

• Spring and Summer: Pollen from blooming plants is a common trigger.
• Fall: Ragweed pollen and other late-blooming plants can affect allergy sufferers.
• Year-Round Allergies: Pet dander, dust mites, and mold can cause symptoms throughout the year.

Is It Something More Serious?

A stuffy nose and sneezing may seem harmless, but they could indicate something more serious if your symptoms persist or worsen. Look out for these red flags:

• Symptoms last longer than a few days or worsen over time
• Nasal discharge is thick, yellow, or green, or contains blood
• Swollen or tender lymph nodes
• A sore throat so severe you can’t eat or drink
• Difficulty completing daily tasks
• Difficulty breathing or shortness of breath
• Sudden severe symptoms that resemble an allergic reaction, such as swelling of the face or throat, wheezing, or a drop in blood pressure, which could be signs of anaphylaxis (a medical emergency)

Other Causes of Allergy-Like Symptoms

Several other conditions can mimic allergy symptoms, including:

• Sinusitis (sinus infection)
• Non-allergic rhinitis (nasal inflammation from irritants or infections)
• Nasal polyps or a deviated septum
• Asthma or COPD
• Nasal and sinus cancers

If your symptoms don’t improve with antihistamines or typical allergy treatments, they might not be caused by allergies.

Diagnosing the Cause

To determine whether you’re dealing with allergies or something else, your doctor will review your symptoms, medical history, and possibly perform diagnostic tests. These may include:

• Skin tests to check for allergic reactions
• Blood tests to measure specific antibodies
• Nasal smears to check for other causes of symptoms

If you see a doctor soon after symptoms appear, a physical exam can help clarify what’s causing your discomfort.

When to Contact Your Doctor

It’s always a good idea to contact your doctor if you’re unsure about your symptoms or if they’re getting worse. Some signs you should consult a healthcare professional include:

• This is your first experience with these symptoms
• Symptoms are getting progressively worse
• Pain develops in other areas of the body
• You’re feeling too sick to carry out daily tasks
• Symptoms began after exposure to an irritant or injury
• You have a high risk for conditions like nasal or sinus cancer
• Over-the-counter allergy medications aren’t helping
• Symptoms have lasted more than a few days with no improvement

The Bottom Line

Allergies can cause symptoms that overlap with many other conditions, including colds and sinus infections. While it’s often possible to tell the difference by the timing and duration of symptoms, your doctor can help definitively determine the cause and recommend the best course of treatment.