I was doing some research on Internet about the swelling I see in certain groups of muscles.  I know it is there, I can see it , palpate it and work on it to relieve it.  Just needed to describe it.  Here is an interesting way to look at the cause.

Treating and Preventing DOMSJohndavid Maes, and Len Kravitz, Ph.D. Articles Reviewed: Connolly, D.A.J., S.P Sayers, and M.P. McHugh. Treatment and prevention of delayed onset muscle soreness. J. Strength Cond. Res. 17(1):197-298. 2003. Szymanski, D.J. Recommendations for the avoidance of delayed-onset muscle soreness. J. Strength Cond. Res. 23(4): 7-13. 2001.  In their review, Connolly et al. (2003) explain that the injury itself is a result of eccentric exercise, causing damage to the muscle cell membrane, which sets off an inflammatory response. This inflammatory response leads to the formation of metabolic waste products, which act as a chemical stimulus to the nerve endings that directly cause a sensation of pain. These metabolic waste products also increase vascular permeability and attract neutrophils (a type of white blood cell) to the site of injury. Once at the site of injury, neutrophils generate free radicals (molecules with unshared electrons), which can further damage the cell membrane. Swelling is also a common occurrence at the site of membrane injury, and can lead to additional sensations of pain. Connolly et al. also note the importance of differentiating DOMS from other injuries such as muscle strains. This difference is important to appreciate because when muscle strain is sustained from vigorous exercise, particularly eccentric exercise, it can severely worsen the injury. In contrast, in a muscle that is experiencing DOMS, continued eccentric exercise is still possible without further muscle damage. When dealing with DOMS it is important to differentiate it from muscle strains, recognizing that continued exercise is still possible with DOMS, but not with muscle strain.