A Parent's Guide to Whooping Cough Symptoms

By Dr. Sam Ahn, MD (Family Medicine Specialist) | August 25, 2025

Hearing that whooping cough (pertussis) is making the rounds is enough to make any parent’s heart skip a beat. Recently, public health officials have noted a rise in cases across the United States, reminding us that this disease is still a very real threat. This illness, sometimes called the "100-day cough," is known for its scary-sounding coughing fits and is extremely contagious. Understanding the specific whooping cough symptoms helps you know when to be concerned and what actions to take to protect your family.

Quick Answer: Whooping cough is a serious bacterial infection of the lungs and airways. It progresses from cold-like symptoms to severe coughing fits that often end in a "whooping" sound. It is most dangerous for babies under 6 months old, and early treatment with antibiotics is critical.

The Three Stages of Whooping Cough

Unlike a simple cold, whooping cough changes over time, typically moving through three distinct stages. Knowing these stages can help you identify what's happening.

Stage 1: The "Cold" Stage (First 1-2 Weeks)

At first, it looks exactly like a common cold with a runny nose, mild fever, and a light cough. This is when a person is most contagious, and it's nearly impossible to know it’s pertussis.

Stage 2: The "Coughing Fit" Stage (Can last 1-6 weeks)

This is when the hallmark symptoms appear. The cough becomes severe and happens in spells, or fits. During a fit, a child may cough repeatedly without a chance to breathe, then take a sharp breath in that causes a high-pitched "whoop" sound. However, many infants and some older children never make the whoop sound. They might just have coughing spells, turn red or purple, or even briefly stop breathing (apnea). It can be very helpful to use the Symptom Notepad in the FeverCoach app to describe what the cough sounds like and how long the fits last.

Stage 3: The Recovery Stage (Weeks to Months)

The coughing fits become less frequent and less severe, but a lingering cough can last for weeks or even months as the body slowly heals.

Who Is Most at Risk?

While anyone can get whooping cough, it is most severe and life-threatening for babies, especially those under 6 months of age. Because their immune systems are still developing and they haven't completed their first series of vaccines, they are highly vulnerable to serious complications like pneumonia, seizures, and other breathing emergencies.

What to Do: A Simple Action Plan

1. Focus on Prevention (Vaccines): Vaccination is the best tool we have. Ensure your child is up to date on their DTaP shots (given at 2, 4, 6, and 15-18 months, with a booster at 4-6 years). Pregnant mothers should get the Tdap vaccine in the third trimester to pass protective antibodies to their newborn. All adults who are around the baby should also be up to date on their 10-year Tdap booster to create a "cocoon" of protection.

2. Provide Comfort, But Skip the Cough Syrup: Keep your child hydrated and use a cool-mist humidifier to soothe their airways. Important: Do not give over-the-counter cough medicine. It is not effective for the pertussis cough and is not safe for young children.

3. Get Clear Guidance: When a cough sounds severe or you just feel that something isn't right, you need answers you can trust. Describe the situation to our AI Coach in the FeverCoach app for immediate, personalized advice on your next steps.

When to Call the Doctor Immediately

Whooping cough must be diagnosed by a doctor and is treated with specific antibiotics. Early treatment—ideally within the first 3 weeks of symptoms—is key to shortening the illness and preventing its spread. Call your doctor right away, or seek emergency care if your child:

• Has coughing spells that end in vomiting, exhaustion, or a "whoop" sound.

• Stops breathing, even for a moment, or their face or lips turn blue or purple.

• Is having trouble breathing or seems to be struggling for air.

• Is a baby under 6 months old with any symptoms that look like a cold or cough.

These are critical warning signs because whooping cough can lead to serious complications like pneumonia. Don't wait.

To prevent spreading the illness:

• Isolation: If diagnosed, your child will need to stay home and away from others, usually for the first 5 days after starting antibiotics, to no longer be contagious.

• Family Protection: Ask your doctor if preventative antibiotics are needed for other close family members to stop the infection from spreading.

Still have questions?

Get personalized answers in seconds from our AI Coach in the FeverCoach app.