If a lightning strike is a sufficient distance from the observer, sound from the strike will not be heard. These silent bolts are called heat lightning. Lightning bolts produce thunder, but the thunder sound does not travel all the way to the observer if the observer is too far away. The movement of sound in the atmosphere depends on the atmospheric properties of the air such as temperature and density.
Collagen vascular diseases are autoimmune diseases that affect connective tissues, and occur when the bodyâs immune system attacks its own tissues and organs. Lupus is often characterized by a facial rash on both cheeks. Lupus patients may experience fatigue, joint pain, skin lesions and shortness of breath.
Although collagenous colitis and lymphocytic colitis display different characteristics under magnification, the symptoms of the two forms of microscopic colitis are virtually identical. The chief complaint with both conditions is chronic watery diarrhea with no sign of blood in the stool, observes Dr. Valentine.