Membranes can be damaged through two mechanisms: the lipids themselves are damaged either from toxins or from oxidative stress (see Oxidative Stress); or the lipids are inflexible, like rubber tubing where cracks appear due to plastic that has gotten old and dried out. Membranes should be flexible and malleable like a balloon, called membrane fluidity—they should give somewhat when poked from one direction. When they don’t, they can burst.
