15-year-old Sienna Ringeisen, a US citizen, was diagnosed with brain tumour at the age of 2. When her parents found out that she collapsed on to the ground, they called 911 and she was quickly flown to a children's hospital.

The tumour was between the size of a orange and a grape fruit.

Before they found out that she got sick, Sienna's parents saw their child to be a very happy, wild, a kid full of joy. But, the more the tumor grew, the less happy she became, and the less she was herself.

The symptoms were there but they were very small signs.

Signs depend on where the tumour is located in the brain, and symptoms can include -

Headache that gets worse with time may be an early sign of brain tumour. It may or may not be associated with vomiting. Moreover, not all brain Tumours have headache as an early sign of tumour in the brain.
Seizures may be another early symptom of brain tumour. The neurologist will evaluate whether seizures are because of brain tumour or other cause.
Nausea/vomiting
Blurred vision
Imbalance of body (Gait abnormalities)

Other symptoms of brain tumours develop based on the part of brain involved. Tumors in:

Parts of Cerebrum (outer part of brain) - weakness, numbness of one side of the body.
Areas close to the cerebrum - Difficulty to speak
Front part of cerebrum - May hamper thought process, or affect personality development as well as language.
Basal ganglia - can cause abnormal movements of body.
Cerebellum - Difficulty with regular activities like walking.
Areas near to the pituitary or optic nerves cause problems with vision
Areas near to cranial nerves - loss of hearing, difficulty swallowing

As a child, Sienna had to go through big surgeries, chemotherapy and even radiation.

Watch Dr. Sheh Rawat, Senior Consultant & Chief of Head & Neck Radiation Oncology, Rajiv Gandhi Cancer Institute, talking about his speciality in head & neck cancers and brain tumors.

I was miserable, tired. It was hard to go through but I did. But that was not enough - I had to go through it again. I was diagnosed with another brain tumor at the small age of 5. This time, it was the size of a grape. Not as bad as the last, but still pretty bad.

Sienna had the complete support from her family and friends.

Going through all of that was tough and it effected me a lot and it still does every day but I get through it because of my family and friends. They stuck by me all the way and I'm thankful for that. To all the people in the world find really good people and hold to them tight as possible and never let them go ever. If you or someone you know starts feeling like they're not themselves, don't just stand there - Try to figure it out.