if tumors are abnormal growth of tissues how then does it cause health complications if they are just tissues

Question: if tumors are abnormal growth of tissues how then does it cause health complications if they are just tissues
- Keywords:
  tissue,
  tumor
Asked by rapid.scientist to Mary, Loice, George, George, Diana on 30 May 2019.
- Diana Nyabundi answered on 30 May 2019:
  
  Tumors are abnormal growth of tissues just like any other tissue it requires blood (nutrients and oxygen) to survive thus denying the regular tissues the same it is quite selfish. additionally it p presses against normal tissue impairing its function eg in the brain.

Question: if tumors are abnormal growth of tissues how then does it cause health complications if they are just tissues