27-year-old Nathaniel Zachariah Tan passed away on Aug. 12 after battling a Grade 4 cerebral Arteriovenous Malformation (AVM), a rare and serious condition he first discovered during National Service.

In loving memory of the 27-year-old Nathanieal Zachariah Tan whose passing on Aug. 12, gave hope to others through the donation of four vital organ
In loving memory of 27-year-old Nathanieal Zachariah Tan, whose passing on Aug. 12 gave hope to others through the donation of four vital organs.
Image credit: Shin Min Daily News

Normally, arteries carry blood to the brain, and veins carry blood back to the heart, with capillaries in between to slow the flow and deliver oxygen to brain tissue. In an AVM, there are no capillaries. Instead, arteries connect directly to veins in a tangled knot of blood vessels.

This abnormal shortcut causes high-pressure blood flow, which can:

  • deprive brain tissue of oxygen
  • weaken blood vessel walls
  • sometimes lead to bleeding in the brain (hemorrhage), stroke, or seizures

It’s usually something people are born with, though not always diagnosed until later when symptoms (like headaches or seizures) appear.

In his final moments, Nathaniel chose selflessness by donating his kidneys, liver, and iliac arteries, giving four patients a second chance at life.

His mother, Queenie Tan, 62, described him as a loving son who had always expressed his wish to donate his organs if anything happened to him.

Sadly, Nathaniel and his fiancée Cheryl Lim were just months away from tying the knot this November, after being together for eight years. He had even proposed to her in Taiwan last year with a song he wrote himself.

Nathaniel’s health struggles began much earlier in life. He suffered from frequent headaches as early as Primary Five, which his family thought were normal at the time. It wasn’t until he enlisted in the army that the headaches became more severe, prompting him to undergo an MRI scan, which revealed his AVM diagnosis.

MRI scans showing Nathaniel's AVM diagnosis
MRI scans showing Nathaniel’s AVM diagnosis.
Image credit: @zakeriea (Instagram)

From February to August 2025, his condition worsened quickly:

  • Feb 2025: An MRI revealed a Gamma Knife–induced cyst, a rare complication in about one in ten cases
  • July 7, 2025: The cyst had grown to 7cm, and doctors suspected internal bleeding
  • July 28, 2025: Admitted to A&E after experiencing numbness on the left side of his body
  • Late July 2025: Underwent two emergency brain surgeries. He suffered a stroke, brain trauma, and severe intracranial pressure that damaged his brain stem
  • Aug 12, 2025: Fell into a coma, declared brain dead at 12pm. That evening, he donated his organs, saving four lives

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