It is difficult to predict how long it will take for an individual with a brain tumor to display symptoms, according to WebMD. Not all brain tumors are associated with symptoms, and some tumors are not even detected until after death. Diagnostic testing is necessary.
Tumor symptoms are generally caused by the tumor pressing on a particular part of the brain, states WebMD. These symptoms can also be due to brain swelling or inflammation resulting from the tumor. Common brain cancer symptoms include headache, weakness, seizures and degraded coordination. Less specific symptoms are nausea, vomiting, vision abnormalities, difficulty with speech, and changes in intellectual or emotional capacity. Immediate medical care is necessary if the individual suffering a brain tumor experiences new or worsening symptoms.