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 the Signs and Symptoms. Crohnâs disease can affect any part of the GI tract. While symptoms vary from patient to patient and some may be more common than others, the tell-tale symptoms of Crohnâs disease include: Symptoms related to inflammation of the GI tract: 1  Persistent Diarrhea.2  Rectal bleeding.ecognizing the Signs and Symptoms. Crohnâs disease can affect any part of the GI tract. While symptoms vary from patient to patient and some may be more common than others, the tell-tale symptoms of Crohnâs disease include: Symptoms related to inflammation of the GI tract: 1  Persistent Diarrhea. 2  Rectal bleeding.