When does the brain stop growing? Neurosurgeon explains

A child recognising their mother for the first time. A student writing their very first letter. A musician composing a melody that stirs the soul. A mother gently placing her hand on her child's head. A patient moving their limbs again after a complex surgery. Behind every single one of these deeply human moments lies a single, profound miracle: the human brain.

The human brain is one of the most complex structures in the known universe. Astronomers estimate there are about 100 billion stars in our Milky Way galaxy. If that seems mind-boggling, consider this: the human brain, weighing just 1.4 kilograms, contains approximately 86 billion neurons, or nerve cells. The number of thinking cells inside our heads is almost equivalent to the stars shining in the night sky. But while those cosmic stars remain isolated by light-years of empty space, our neurons are intricately interconnected, forming hundreds of trillions of synapses. This complex web is what shapes our thoughts, memories, emotions, dreams, and ultimate identity. Dr Sareesh Kumar MK, senior Consultant and Head of Neurosurgery and Spine Surgery at Mar Sleeva Medicity, Palai, explains. 

The organ that gives life its meaning
While the heart sustains physical life by pumping blood, it is the brain that gives that life its meaning. As a neurosurgeon, I witness both sides of this miracle every single day. A person laughing and talking one moment can have their life altered in an instant by a minor brain haemorrhage. Conversely, after hours of delicate brain surgery, seeing a patient's finger twitch for the first time brings an irreplaceable wave of hope to a waiting family. That is the power of the brain—the greatest marvel of human existence.

Some facts about this organ are truly astonishing. Despite accounting for only 2 per cent of our body weight, the brain consumes nearly 20 per cent of our total energy. Millions of electrical signals zip through its pathways every second. Yet, the brain itself cannot feel pain. It lacks pain receptors, which is why neurosurgeons can perform awake craniotomies—brain surgeries where the patient remains conscious and communicative while we operate.

When does the brain stop growing?
Science once believed that the brain stops developing after a certain age. Today, we know the exact opposite is true. Through a remarkable phenomenon called neuroplasticity, the brain retains the ability to create new connections, learn, and reorganise itself throughout our lives, even after sustaining injuries.

Even when a stroke or trauma damages a portion of the brain, it refuses to concede defeat. It begins training neighbouring healthy cells to take over the functions of the injured areas by forging new neural pathways. The survival and rehabilitation of stroke survivors is a testament to this resilience. When a patient who has lost all mobility due to a stroke learns to walk or write again after months of intensive physiotherapy, it is because healthy brain cells are actively stepping up to assume the workload.

The scientific truth is simple: 'Neurons that fire together, wire together.' Through repetitive practice, the brain carves out new operational pathways. When a father recovering from a stroke finally holds his daughter's hand again, it is not just a triumph of medical science—it is a victory of the brain's incredible survival mechanism.

Have you ever wondered why we sleep? Sleep, too, is a marvel of neurological engineering. When we sleep, our bodies rest, but our brains go to work. It organises the day's memories, flushes out metabolic waste, and prepares itself for the challenges of the coming day. This is why chronic sleep deprivation so severely impacts memory, decision-making, and overall mental health.

The biological supercomputer vs AI
We live in the era of Artificial Intelligence. Computers can perform complex calculations, generate artwork, and master languages. Yet, they remain light-years behind the biological supercomputer inside our heads. While machine learning algorithms process code and data, they cannot experience emotions. A machine can analyse a photograph, but it cannot feel the pure joy behind a baby's first smile, empathise with the tears of a grieving friend, or comprehend the tender warmth of human love. Beyond pure logic lies a realm of consciousness and emotional depth that belongs uniquely to the human brain.

Brain health is a fundamental human right
Despite its power, this vital organ is increasingly under threat. Neurological disorders—such as strokes, epilepsy, Parkinson's disease, Alzheimer's, brain tumours, and traumatic injuries—affect millions of families worldwide. Currently, over 3.4 billion people live with some form of neurological condition, making it the leading cause of disability globally. Alarmingly, a vast majority do not have access to timely neurological care.

This inequality highlights the urgency of this year's World Brain Day theme: 'Brain Health for All'. Quality neurological care and awareness must not remain the privilege of a select few. When a stroke occurs, every second counts—' time is brain', as millions of neurons die with every passing minute. Building healthcare systems that extend neurological care from multi-speciality urban hospitals to remote rural communities is a global necessity.

How to keep your brain healthy
Fortunately, protecting your brain is largely within your hands. Simple lifestyle choices can preserve cognitive health for years to come. Managing blood pressure and diabetes, avoiding smoking, exercising regularly, securing adequate sleep, eating a balanced diet, learning new skills, reading, enjoying music, and maintaining active social connections all work wonders for the brain.

Recognising the early warning signs of a stroke and reaching a hospital immediately can save not just a life, but an entire family's future. 'Time is brain' is not just a slogan; it is a clinical reality.

This World Brain Day, let us make a pledge: to cherish and protect our brains just as we do our hearts; to safeguard our memories, dreams, and thoughts as closely as we monitor our blood pressure; and to exercise our minds just as we train our bodies.

Material wealth and professional status can be lost and rebuilt. But if we lose our memories, our thoughts, and our ability to dream, we lose ourselves. Take care of your brain—because it is what makes you 'you'.