Colds rarely cause serious complications. In about 1% of cases, a cold can lead to other complications, such as sinus or ear infections. It can also aggravate asthma and, in uncommon situations, increase the risk for lower respiratory tract infections.he influenza virus mutates (changes) rapidly as it moves from species to species. While most avian influenza (bird flu) virus strains are relatively harmless, a few develop into highly pathogenic avian influenza, which can be very deadly for domesticated poultry.
For other uses, see Gerd. Gastroesophageal reflux disease (GERD), also known as acid reflux, is a long-term condition where stomach contents come back up into the esophagus resulting in either symptoms or complications. Symptoms include the taste of acid in the back of the mouth, heartburn, bad breath, chest pain, vomiting, breathing problems, and wearing away of the teeth.
1 Gastroesophageal reflux disease (GERD) is a condition in which gastric contents and acid flow up from the stomach into the esophagus (food pipe). 2  About half of American adults experience GERD at least once a month.3  People of all ages are susceptible to GERD.verview. 1  Gastroesophageal reflux disease (GERD) is a condition in which gastric contents and acid flow up from the stomach into the esophagus (food pipe). 2  About half of American adults experience GERD at least once a month.