The symptoms of whooping cough usually take 6-20 days to appear after infection with the Bordetella pertussis bacterium. This delay is known as the incubation period.
Whooping cough tends to develop in stages, with mild symptoms occurring first, followed by a period of more severe symptoms, before improvement begins.
The early symptoms of whooping cough are often similar to those of a common cold and may include:
- runny or blocked nose
- watering eyes
- dry, irritating cough
- sore throat
- slightly raised temperature
- feeling generally unwell
These early symptoms of whooping cough can last for one to two weeks, before becoming more severe.
The second stage of whooping cough is often called the paroxysmal stage and is characterised by intense bouts of coughing. The bouts are sometimes referred to as 'paroxysms' of coughing.
The paroxysmal symptoms of whooping cough may include:
- intense bouts of coughing, which bring up thick phlegm
- a 'whoop' sound with each sharp intake of breath after coughing (although this may not occur in infants and young children, see below)
- vomiting after coughing, especially in infants and young children
- fatigue (tiredness) and redness in the face from the effort of coughing
Each bout of coughing usually lasts between one and two minutes, but several bouts may occur in quick succession and last several minutes. The number of coughing bouts experienced each day varies, but is usually between 12 and 15.
The paroxysmal symptoms of whooping cough usually last at least two weeks, but can last longer, even after treatment. This is because the cough continues even after the Bordetella pertussis bacterium has been cleared from your body.
Infants and young children
Infants younger than three months may not make the 'whoop' sound after coughing, but they may start gagging or gasping, and may temporarily stop breathing. It is possible for whooping cough to cause sudden unexpected death in infants (see Whooping cough - complications for more information).
Young children may also seem to choke or become blue in the face (cyanosis) when they have a bout of coughing. This looks worse than it is, and breathing will quickly start again.
Adults and older children
In adults and older children, the paroxysmal symptoms of whooping cough are far less severe than they are in young children, and may appear more like the symptoms of a milder respiratory infection, such as bronchitis.
Eventually, the symptoms of whooping cough gradually start to improve, with fewer and less extreme bouts of coughing occurring. This period of recovery can last up to three months or more.
However, intense bouts of coughing may still occur during this period.