He estimated how many species of insects lived on each plant species in England, and then extrapolated that figure across the whole planet. âIf we say 400,000, we shall, perhaps, not be very wide of the truth,â he wrote. Today, scientists know the Westwood figure is far too low.
Symptoms: A chronic dry cough that's worse at night, disturbing sleep, and sometimes with wheezing and shortness of breath. Causes: An irritating night cough is often the first sign of asthma, especially in children, but you can develop it at any age. It's also a sign asthma is worsening or not being well controlled.
If your body is low in iron, swelling and irritation in the back of your throat could be a symptom, which can lead to coughing. If this sounds familiar, then an iron supplement may be all you need. Check your drugs: Meds, like ACE inhibitors prescribed for high blood pressure, can create the side effect of a dry cough.