Common Cold, Flu, Allergies, Sinuses, Rhinitis & Sneezing

Common Cold, Flu, Allergies, Sinuses,

Rhinitis & Sneezing

Medical Library Basics: Colds & Flu (MedlinePlus)

TeenThreads mission: No panic. No misinformation. Just clear facts — so you can tell the difference between a cold, flu, allergies, and sinus problems, and know when it’s time to get help.

Important: This page is educational and does not replace medical care. If symptoms are severe, fast-worsening, or scary, seek urgent care.

Quick Jump

What These Conditions Are
Normal vs Not-Normal (Red Flags)
Cold vs Flu vs Allergies (Quick Compare)
Common Cold
Flu (Influenza)
Allergies
Rhinitis (Allergic & Nonallergic)
Sinuses & Sinusitis
Sneezing: Common Causes
Treatment & Relief
Prevention & Staying Well
When to See a Clinician
Trusted Resources

What These Conditions Are

Many teens get congestion, sneezing, and sore throats — but the cause matters. Some are caused by viruses (like the common cold or flu),
while others are triggered by allergens or irritation (like allergies or nonallergic rhinitis). Sinusitis can happen after a cold or when
swelling blocks normal sinus drainage.

Trusted overviews:
MedlinePlus – Colds and Flu
MedlinePlus – Allergies
MedlinePlus – Sinusitis
NIH Flu, Cold or Something Else?

Normal vs Not-Normal (Red Flags)

Often Normal (Common, Usually Not Dangerous)

Sneezing, runny nose, mild sore throat
Stuffy nose for a few days with a cold
Mild cough that improves over 1–2 weeks
Itchy eyes/nose during allergy season
Low fever with a cold (some people), especially early on

Get Checked Soon (Possible Red Flags)

Difficulty breathing, wheezing, or fast breathing
Chest pain, blue lips/face, or severe weakness
High fever or fever that lasts several days
Severe headache, stiff neck, confusion, or fainting
Sinus symptoms that last > 10 days without improving, or “improve then suddenly get worse”
Severe face pain/swelling or swelling around the eyes
Dehydration signs (very dry mouth, dizziness, peeing much less than normal)

CDC – Flu Symptoms & Emergency Warning Signs
CDC – Sinus Infection (when to seek care)

Could this be Covid-19, or just an allergy?

Could this be a common Covid-19,
seasonal allergies,
common cold, flu?

Quick Comparison

Source: AllergyFree

Cold vs Flu vs Allergies (Quick Comparison)

Fast “Clue Check”

Cold: gradual start; stuffy/runny nose, sore throat, mild cough; usually mild fatigue.
Flu: often hits fast; fever, body aches, chills, strong fatigue; cough is common.
Allergies: no fever; itching (eyes/nose), sneezing, clear runny nose; symptoms repeat with triggers.
Sinusitis: facial pressure/pain, thick nasal drainage, congestion; can follow a cold.

CDC – Flu vs Cold

Common Cold

The common cold is a viral infection that affects the nose and throat. Most colds improve in about a week, but a cough can last longer.

Runny or stuffy nose
Sore throat
Sneezing
Mild cough
Sometimes low fever and mild tiredness

Trusted basics:
MedlinePlus – Common Cold

Flu (Influenza)

The flu is also a viral infection, but it can be much more intense than a cold. It often starts suddenly and can cause fever, strong aches,
and major fatigue. Some people are at higher risk for complications.

Fever or feeling feverish/chills
Body aches
Cough and sore throat
Strong fatigue
Sometimes vomiting/diarrhea (more common in kids/teens than adults)

Trusted basics:
CDC – Influenza (Flu)
MedlinePlus – Flu

Allergies

Allergies happen when your immune system reacts to something that is usually harmless (like pollen, dust mites, mold, or pet dander).
Allergy symptoms can look like a cold, but allergies usually do not cause fever.

Sneezing
Itchy nose/eyes/throat
Runny nose (often clear)
Watery eyes
Congestion

Trusted basics:
MedlinePlus – Allergies
CDC – Asthma (allergies can be linked for some people)

Rhinitis: Allergic & Nonallergic

Rhinitis means inflammation inside the nose. It can be allergic (triggered by pollen, pets, dust) or nonallergic
(triggered by irritants like smoke, strong scents, weather changes, or infections).

Stuffy nose
Runny nose
Sneezing
Postnasal drip (mucus dripping down the throat)

MedlinePlus Encyclopedia – Rhinitis

Sinuses & Sinusitis

Your sinuses are air spaces in the bones around your nose. Sinusitis can happen when swelling blocks drainage and germs grow.
Most sinus infections start after a cold or allergy flare.

Common sinus symptoms

Facial pressure/pain (cheeks, forehead)
Thick nasal discharge
Stuffy nose that won’t clear
Reduced sense of smell
Cough (often worse at night from postnasal drip)

Clues it may need evaluation

Symptoms last more than 10 days with no improvement
Severe symptoms (high fever, intense face pain)
Symptoms improve, then suddenly get worse

MedlinePlus – Sinusitis
CDC – Sinus Infection (Antibiotic Use & When to Seek Care

Sneezing: Common Causes

Sneezing is a body reflex that helps clear irritants from the nose. It’s common and usually not dangerous.

Colds (viruses)
Allergies (pollen, dust mites, pets)
Smoke, strong fragrance, cleaning chemicals
Dry air
Rhinitis (allergic or nonallergic)

Allergies vs seasonal flu, cold, & ither viruses.

Dr. Chris Thompson discusses the symptoms and differences between allergies and the seasonal flu, a cold, or other viruses.

Some symptoms of allergies, the common cold, & COVID-19 overlap
[Source: Aspire Allergy & Sinus]

Treatment & Relief: Safe & Teen-Realistic

1) Comfort care for colds & mild symptoms

Rest + fluids: helps your body recover
Warm drinks: can soothe sore throat
Honey for cough (only if you’re older than 1 year)
Saltwater gargle: can calm throat irritation
Humidified air: can ease congestion in dry climates

2) Congestion & sinus pressure basics

Saline nasal spray can help loosen mucus
Warm shower/steam may ease stuffiness
Head elevation can help at night

3) Allergy control basics

Limit triggers (pollen, dust, pets) when possible
Shower after heavy pollen exposure
Keep windows closed during high pollen days

Medicine safety note: If you use over-the-counter medicine, follow the label exactly. Do not take extra doses to “knock symptoms out.”
If you have asthma, chronic illness, or take other medicines, ask a clinician/pharmacist first.

Trusted symptom-care resources:
MedlinePlus – Cough
MedlinePlus – Sore Throat
MedlinePlus – Nasal Congestion

Prevention & Staying Well

Handwashing: one of the best ways to reduce spread of viruses
Cover coughs/sneezes: with tissue or elbow
Stay home when sick (when possible) to protect others
Sleep + hydration: helps immune function
Flu vaccine: lowers risk of flu and severe outcomes

CDC – Prevent Seasonal Flu
CDC – Flu Vaccine

When to See a Clinician

Breathing feels hard, tight, or wheezy
High fever or fever that won’t go away
Severe sore throat with trouble swallowing or drooling
Severe headache, stiff neck, confusion, or fainting
Sinus symptoms last > 10 days or suddenly worsen after improving
Signs of dehydration or you can’t keep fluids down
You have a medical condition that raises complication risk (ask your clinician)

CDC – Flu Symptoms & Warning Signs
MedlinePlus Encyclopedia – Fever

Trusted Resources

TeenThreads Final Word

Sniffles are common, but guessing wrong can lead to the wrong choices. The power move is noticing patterns:
flu hits hard and fast, allergies itch and repeat, colds usually build slowly, and
sinus issues often come after congestion.
If your symptoms are intense, long-lasting, or affecting breathing, get help – early care is smart care.

TeenThreads note: This page is curated for teens using trusted government and medical library sources.

Last updated: February 5, 2026

TeenThreads Content Team