Overview. If you frequently experience shortness of breath or you hear a whistling or wheezy sound in your chest when you breathe, you may have asthma â a chronic condition that causes inflammation and narrowing of the bronchial tubes, the passageways that allow air to enter and leave the lungs.
1 At 47,958 kilometres (29,800 miles) in total length, the Pan-American Highway is the longest road in the world.  The road starts in Alaska, North America and ends in the lower reaches of South America.
I-40, the third-longest in the country, which winds through eight states, comes in third for deadly crashes. I-90, the longest highway in the country, did not make the list. The full list of most dangerous highways is as follows: I-10.