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.
Recognizing Symptoms of Hemolytic Uremic Syndrome. The symptoms of HUS vary. They can result from E. coli toxins, kidney damage, and the loss of red blood cells and platelets. Symptoms could include: 1  bloody diarrhea. 2  abdominal pain. 3  pale skin. 4  irritability. 5  fatigue. 6  fever. 7  unexplained bruises or bleeding. 8  decreased urination. 9  abdominal swelling.