| Most often the blockage occurs in the urethra after a stone or a mixture of crystal, mucus, and other organic material forms a plug. |
| Kidney stones are another source of blockage that may obstruct the path of urine. |
| A common cause of blockage is when people attempt to clean the ear, for example with a cotton bud. |
| If the embolus reaches a blood vessel it cannot flow through, a blockage occurs. |
| Many foods can be dangerous for small children since they can aspirate the items, which will result in blockage of the breathing passages. |
| This blockage causes fibroid muscle cells to degenerate and form scar tissue, which causes fibroids to shrink. |
