Can your lymphatic system malfunction? Can it be harmed, or make you sick?
Yes, the lymphatic system may malfunction.
Mechanical blockage of lymphatic flow occurs in infection by filarial worms. The disease vector is culex mosquito and the disease caused is elephantiasis .
In case of protein defficiency disease, named Kwashiorkor, increased formation of lymph (colloidal osmotic pressure of blood decreases due to lower plasma protein concentration, hence more water drains from blood to tissues) causes swelling in legs. Swelling of parts of body due to accumulation of interstitial fluid is called oedema .
To understand oedema, that is formation of more of tissue fluid in body, you may also read this.
Then there are swollen lymph nodes , associated with infections of tuberculosis, plague, etc. I must also mention lymphoma , malignant tumour of lymphatic system.