Roona Begum, a 18-month-old girl from Tripura, is suffering from a rare medical condition, Hydrocephalus, which causes her head to swell up to a huge size.

Hydrocephalus also referred to as "water on the brain" is a medical condition that causes abnormal accumulation of fluid in the brain's cavities.

Roona's mother Fatima said that her daughter has been suffering from Hydrocephalus since she was born and doctors are unable to cure or improve her condition, according to Reuters.

Her father, Abdul Rehman, said they are unable to bear the medical expenses due to financial constraints. He said that only a "miracle" can save his daughter.

"Day by day, I saw her head growing too big after she was born. It's very difficult to watch her in pain. I pray several times a day for a miracle -- for something to make my child better," Rehman told AFP.

Rehman, who works in a brick factory, earns approximately ₹150 per day. When doctors suggested that he take Roona to a specialist in Kolkata, he denied saying he did not have enough money for this.

Due to Hydrocephalus, Roona's head swelled to a circumference of 91-centimetres (36-inches) putting pressure inside her skull, according to AFP.

Doctors have said that it's too late to save her life, as surgery could be fatal.

"It is too late to do anything now. The brain will be damaged, and draining the fluid can cause problems by causing the brain to collapse and bleed. Roona should really be left untreated. She will not make any recovery and will not ever live a life of any independence," Sanj Bassi, Consultant Adult and Paediatric Neurosurgeon at Kings College Hospital told Daily Mail.

Every year more than 400,000 children develop this condition and a majority of them live in developing countries. Hydrocephalus goes untreated because neurosurgical care is not available in these countries.

According to MedicineNet.com, Hydrocephalus is a condition that affects about one out of every 500 children. Rapid increase in head circumference or abnormal huge head size is the most obvious symptom of hydrocephalus that can be identified in children or infants.

Other symptoms includes vomiting, irritability, seizures, sleepiness, sunsetting eyes and separated sutures.

Check out the photos here:

Runa Begum
Runa Begum
Runa Begum
Runa Begum (Reuters)
Runa Begum
Runa Begum (Reuters)