Although a persistent cough can interfere with your toddler's sleep and make her sound very ill, coughing is not usually a sign of serious illness. Coughing protects your toddler's airways by keeping them clear of mucus and other secretions. A dry, hacking cough usually means that your toddler has an allergy or mild cold, but take your child to a doctor for an evaluation if he develops a high fever along with the coughing, if he starts to wheeze or breathe rapidly or if the cough persists for more than a week.
Pay careful attention to your child's cough so that you can describe it to your doctor. Tell your doctor about any other symptoms that accompany the cough, such as a runny nose or watery eyes. You should also note whether your child's cough changes by becoming more wet and productive or if it worsens at specific times of the day or night. Your doctor will probably want to hear your child's cough before making a diagnosis, according to the Kids Health from Nemours website, since this is one of the most important clues as to the cause of the cough.
Colds and Flus
If your toddler experiences a runny nose and congestion along with his cough, the BabyCenter parenting website suggests that he is probably sick with a cold or flu virus. Unless he spikes a high fever or has breathing difficulties, the cold will probably run its course in about a week. Although you cannot give a toddler cough medicines due to the U.S. Food and Drug Administration's warning against their use in children under 4, keeping the air moist with a humidifier can often help your toddler sleep better by loosening and thinning out her congestion.
Allergies or Asthma
Postnasal drip due to allergies can lead to a persistent dry, hacking cough and cold symptoms that never seem to go away. A toddler's immature lungs can make them susceptible to seasonal or environmental allergies, like pet dander or smoke. BabyCenter notes that asthma can also cause a dry, hacking cough. The coughing from asthma will often worsen at night and your child might begin to wheeze or experience breathing difficulties.
A cough that persists for more than a week without any other signs of illness might be due to an object stuck in your toddler's lungs. Toddlers increased mobility--and their urge to put things into their mouth--make them more prone than older kids to swallow small toys or chunks of food. If you suspect your toddler inhaled something, seek prompt medical attention.
Even though doctors routinely vaccinate children against pertussis, or whopping cough, outbreaks still occur on a regular basis. This contagious bacterial infection of the windpipe, lungs and throat can cause severe breathing difficulties and even death. Whooping cough will cause your child to cough constantly--as many as 25 times in a single breath, according to the editors of "Parents" magazine. After the cough, you will hear the tell-tale "whoop" as your child inhales and tries to catch his breath. Seek immediate medical attention if you suspect whooping cough; your child will probably need hospitalization and antibiotics to help him heal.