Whooping Cough Symptoms: How to Recognize Pertussis at Every Stage

A cough that started like an ordinary cold has turned into something else entirely. Now there are violent fits, a gasping sound when you finally catch your breath, maybe even throwing up afterward. If that sounds familiar, you may be dealing with whooping cough, also called pertussis, and it is worth taking seriously.

Whooping cough is a highly contagious respiratory infection that can look deceptively mild at first. Knowing how the symptoms change over time, and which ones are red flags, helps you get the right care before it gets worse, especially for babies and the people around them.

What are the symptoms of whooping cough?

Whooping cough symptoms usually begin 5 to 10 days after exposure, though they can take as long as 3 weeks to appear, according to the CDC. The early signs are easy to mistake for a common cold: a runny or stuffy nose, sneezing, a mild fever, and an occasional cough.

What sets pertussis apart is what comes next. Over a week or two, the cough builds into severe, uncontrollable fits. The illness is named for the high-pitched 'whoop' sound some people make as they gasp for air at the end of a coughing spell, caused by air rushing in through a swollen airway. Not everyone whoops, but the pattern of intense, repeated coughing is the hallmark.

The three stages of pertussis

Whooping cough follows a fairly predictable three-stage course. Understanding where you are in that course helps explain why the cough behaves the way it does and how long it may last.

• Catarrhal stage (about 1 to 2 weeks): Cold-like symptoms such as a runny nose, low-grade fever, and a mild, occasional cough. This is when the infection is most contagious, yet hardest to recognize.
• Paroxysmal stage (about 1 to 6 weeks, sometimes up to 10): The coughing fits arrive. Spasms can involve 10 or more rapid coughs without a breath, followed by the inspiratory 'whoop' and frequently vomiting afterward.
• Convalescent stage (weeks to months): The cough gradually eases, but it can linger and may flare up again with later respiratory infections.

What does a whooping cough coughing fit look like?

The coughing fits, called paroxysms, are the most distinctive feature. According to NIH StatPearls, a paroxysm can be a burst of 10 or more rapid coughs without taking a breath, followed by that struggling, high-pitched whoop as the person draws air back in through a swollen glottis.

These fits can leave someone red-faced, exhausted, and short of breath. Vomiting after a coughing spell, known as post-tussive vomiting, is common. Some people also turn briefly bluish during a severe fit. Fits often cluster at night, which can make sleep difficult for weeks.

How long does whooping cough last?

Whooping cough is a long illness, not a quick one. The cough commonly lasts more than 2 weeks and can persist for 2 to 3 months, which is why pertussis is sometimes called the '100-day cough,' per NIH StatPearls.

The most intense coughing usually happens during the paroxysmal stage, then slowly fades through the convalescent stage. Even after the infection clears, the airways can stay sensitive, so a lingering cough does not necessarily mean you are still contagious. Antibiotics tend to help most when started early in the illness.

Whooping cough symptoms in babies

Infants are the group most at risk, and their symptoms can look very different. In young babies, the classic cough may be minimal or even absent. Instead, the main sign can be apnea, where the baby pauses or stops breathing, the CDC notes. That makes pertussis in infants easy to underestimate and genuinely dangerous.

The numbers explain the concern. About one third of infants younger than 12 months who get pertussis require hospitalization, and among infants younger than 6 months that rate rises to 63%, according to the CDC. The most common complications in infants are apnea, affecting 68%, and pneumonia, affecting 22%. Between 2000 and 2017, 307 pertussis deaths were reported to the CDC, with infants younger than 2 months of age accounting for 84.0% of them. Any baby with breathing pauses, a bluish color, or trouble feeding needs emergency care.

When to see a doctor

See a clinician if you or your child has prolonged coughing fits, especially with a whooping sound, vomiting after coughing, or a cough that has lasted more than a week or two without improving. Because whooping cough is highly contagious, an early diagnosis also protects newborns, pregnant people, and anyone with a weakened immune system around you.

Seek emergency help right away if a baby or anyone struggles to breathe, pauses breathing, or turns blue or gray. Doctors can confirm pertussis with a nose or throat swab, blood tests for antibodies, and sometimes a chest X-ray to check for pneumonia, and antibiotics work best when given early, according to the Mayo Clinic. This article is general education and not a substitute for personal medical advice.