Straining

Straining is the forcible, often prolonged exertion of skeletal or smooth muscle against resistance, sufficient to increase intrathoracic and intra-abdominal pressure. Possible causes are straining during defecation (constipation, tenesmus, dyschezia, mechanical obstruction, Parkinson's disease, multiple sclerosis, pelvic floor dysfunction), micturition (BPH, urethral stricture, weakened detrusor muscle, bladder stones), parturition (prolonged labor), or heavy lifting.