But infectious bacteria can make you ill. They reproduce quickly in your body. Many give off chemicals called toxins, which can damage tissue and make you sick. Examples of bacteria that cause infections include Streptococcus, Staphylococcus, and E. coli.
Getty Images/Fuse. Head down: Jet lag symptoms include feeling sleepy during the day in your new time zone. Jet lag is what we call it when your body is reacting to these changes in your environment, which is basically your body taking time to adjust to its new place and time. Symptoms include feeling sleepy during the day in your new time zone, but also having a troubled sleep at night.
Circadian disruptions such as jet lag put us in conflict with our natural sleep patterns, since the shift in time and light cues on the brain forces the body to alter its normal pattern to adjust. This is why jet lag can leave travelers feeling poorly and having more difficulty thinking and performing well.