Your adolescence lasts well up to your 30s. A new, "cool" study as Prof Tara Spires Jones, tells BBC, noted that the human brain does not follow a simple, steady path from birth to old age. Instead, it moves through five clear phases, each marked by a shift in how its networks connect and communicate. The study is conducted by the researchers from the University of Cambridge, who analyzed thousands of brain scans to track how neural connections strengthen, weaken, and reorganize over time.

This large study involved nearly 4,000 people between infancy and age 90 and has now mapped these transitions, offering new insights into why periods of life differ so much in terms of learning, behaviors, and vulnerability to mental health conditions.

Their work shows that the brain remains in an adolescent state far longer than earlier believed and reaches a peak of efficiency only in the early thirties. The findings, published in Nature Communications, highlight striking turning points at the ages of nine, 32, 66 and 83.

The Five Phases Of Brain

Childhood: Birth to Age Nine

The study showed that during childhood, the brain grown rapidly, however, it also begins trimming the vast numbers of synapses formed in early life. This is what helps the brain decide which pathways truly matter. However, this period is not very efficient. It resembles a child wandering without a fixed route, exploring freely rather than moving directly from one point to another. The purpose is exploration, not precision.

Adolescence: Age Nine to 32

A dramatic shift begins around age nine. The brain enters a long stretch of heightened efficiency as it reorganizes its neural networks with remarkable speed and intensity.

This is the phase where mental health vulnerabilities often emerge, since the brain is restructuring at an unusually rapid pace.

This part of the study also breaks the conventional idea that associated adolescence typically with the teenage years. Modern neuroscience suggests it extends into the twenties. This study pushes that boundary even further, indicating that the adolescent phase may last all the way to 32.

During this time, the brain reaches its most efficient point, and many cognitive abilities are thought to peak.

Adulthood: Age 32 to 66

After the long adolescent stretch, adulthood brings stability. The study shows that adulthood actually comes from the age 32, again a shift from what conventionally was believed adulthood to be. This is the brain’s most settled era, lasting more than three decades. Change continues, but at a gentler pace and in a more predictable pattern. The efficiency gained earlier begins to level out. Many people recognize this phase as a period when their cognitive strengths, personality and sense of self feel most consistent. The fireworks of earlier development give way to a steady rhythm.

Early Aging: Age 66 to 83

The period after 66 marks the beginning of early ageing. It does not arrive as a sudden decline. Instead, there are subtle shifts in how different parts of the brain coordinate.

Rather than functioning as one unified network, the brain begins to break into clusters of regions that work more closely within their own groups. It is similar to a band whose members start pursuing individual projects while still occasionally performing together.

Although the study focused on healthy brains, this is also the age when conditions linked to ageing, such as high blood pressure and dementia, begin to appear more frequently.

Late Aging: 83 And Beyond

The final phase begins at around 83. Data for this group was more limited, since it is harder to find older adults with no underlying health issues. Even so, the scans show that the patterns seen in early ageing become more pronounced. The brain’s networks continue to drift apart, and communication between regions becomes less synchronized.

Recent photographs of former US President Donald Trump with the UK’s King Charles III have drawn attention after visible discoloration was observed on his left hand, raising fresh questions about his health.

While Trump’s right hand has appeared discolored in earlier public appearances—a concern previously downplayed by both the former president and the White House—the latest images show similar changes on his left hand as well.

“Trump's right hand has been in bad shape for a long time now, but this picture taken today shows discoloration on the back of his left hand," independent journalist Aaron Rupar wrote on social media platform X.

Speaking to HealthandMe, Dr. Amit Prakash Singh, Consultant - Internal Medicine at the CK Birla Hospital, Delhi, explained the possible underlying causes that can result in hand discoloration. He noted that the condition may be due to:

• Bruising (bleeding under the skin)

This appears as blue, purple, or black patches. It may occur due to minor trauma or sometimes even spontaneously. The use of blood thinners or antiplatelet agents like aspirin can increase the likelihood of bruising. With age, blood vessels become more fragile, making bruising more common.

• Low oxygen or poor circulation

• Swelling (fluid buildup in tissues)

• Infection or inflammation

Dr. Singh advised people "to be concerned if there is sudden swelling in one hand, severe pain or tightness, persistent blue or black discoloration, breathlessness, fever with redness and warmth, or numbness and weakness".

"A purple or blue patch often suggests bruising, blue fingers may indicate circulation or oxygen issues, puffy hands suggest fluid retention, and red, hot swelling points toward infection," the expert said.

However, there is no official medical update on the discoloration in Trump's left hand. Therefore, any claims remain speculative. But it is not the first time that various speculations have been going around about the health of Trump.

Also read: Heat Stroke or Heat Exhaustion? AIIMS Doctor Explains Key Symptoms, How To Prevent

In an interview with The Wall Street Journal, in January this year, the US President informed that he takes aspirin doses more than his doctors recommend, and that is the reason for the bruising seen on his right hand. He has repeatedly said that his health is in "excellent" condition.

In the interview, he said, "They say aspirin is good for thinning out the blood, and I don't want thick blood pouring through my heart."

Trump, now 70, was diagnosed with chronic venous insufficiency, a condition that occurs when veins have trouble moving blood back to the heart. He also showed signs of bruising on his hand, which many attributed to frequent handshaking and to the use of aspirin.

Aspirin may still be considered for some people under 60 or 70 who have a higher risk of heart disease, but this decision should be made carefully. Factors like high blood pressure, high cholesterol, diabetes, smoking history, or a strong family history can influence whether aspirin makes sense for an individual.

With temperatures rising sharply, experts at the All India Institute of Medical Sciences (AIIMS) have warned that young children are significantly more vulnerable to heat stress than adults, urging parents to take preventive measures and recognize early warning signs.

Despite morning showers offering some relief, the national capital still recorded temperatures close to 40°C.

How Extreme Heat Affects Young Kids

Shefali Gulati, Professor, Department of Pediatric Neurology at AIIMS, highlighted that children are predisposed to both heat and cold stress and also tend to get dehydrated more quickly. She noted that global temperatures have been rising over the past few decades, and cited 2020 data from UNICEF, which showed that 76 per cent of children under 18 in South Asia—around 460 million—are exposed to extremely high temperatures, with 83 or more days in a year exceeding 35°C.

Dr. Gulati explained that young children often exhibit early behavioral changes when affected by heat. These can include irritability,

• reluctance to engage in outdoor activities,
• restlessness,
• excessive sweating,
• uneasiness,
• weakness.

She added that heat exposure, when combined with air pollution, can worsen health conditions, particularly in children with lung diseases and asthma.

“Heat can affect all parts of the human body. It begins with irritability and can progress to exhaustion,” she said.

In more severe cases, heat stress may lead to brain exhaustion, loss of consciousness, seizures, dehydration, and electrolyte imbalance.

Dr. Gulati further explained that the human body maintains its core temperature through physiological mechanisms, but these are less efficient in young children. During dehydration, increased blood flow to the skin reduces supply to vital organs like the brain. In patients with pre-existing kidney issues, this can result in acute or chronic injury.

Children with conditions such as cerebral palsy and other neurological disorders may also experience worsening symptoms due to heat exposure.

Further, dehydration can additionally strain the cardiovascular system, thickening blood and leading to tachycardia, thereby affecting cardiac function.

Beyond children, pregnant women exposed to extreme heat may face risks such as preterm birth, neurodevelopmental problems, and cognitive issues in newborns.

Dr Gulati emphasized the importance of fluids, Oral Rehydration Solution (ORS), and small, frequent meals, along with reduced outdoor activity. Preventive measures include wearing loose clothing, avoiding direct sun exposure, and limiting outdoor activities during peak heat hours.

The Importance of Diet: Avoiding Sugary Drinks

Also read: Heat Stroke or Heat Exhaustion? AIIMS Doctor Explains Key Symptoms, How To Prevent

Parmeet Kaur, Chief Dietitian at AIIMS reiterated the importance of proper hydration, food safety, and dietary habits during extreme heat, warning that both children and adults face increased risk of dehydration and related complications.

“One has to avoid consuming extra sugary and salty foods, drinks, and snacks, because if one is consuming highly processed drinks or snacks loaded with sodium and sugar, it may lead to dehydration,” Kaur said.

"Hydration is key, and one should not wait to feel thirsty," she added, stressing the need to consume home-made and simple food.

For immediate management, homemade Oral Rehydration Solution (ORS) can be used, prepared with six teaspoons of sugar and half a teaspoon of salt in one liter of water.

However, she cautioned "against sugary drinks and packaged snacks like chips, explaining that high sugar and sodium content can worsen dehydration while giving a false sense of energy. While these products may create the impression of quick rehydration or an instant energy boost, they can instead contribute to greater fluid loss and increase the risk of severe dehydration.”

Instead, the expert recommended traditional cooling options such as bael sharbat, lassi, sattu, and gond katira. Ingredients like coriander, mint and onion were also suggested as part of summer dietary practices.

The dietician advised small, frequent meals that are easy to digest, including roasted and unsalted chana or peanuts, while avoiding heavy meals.

Food safety is another major concern during the summer. High temperatures increase the risk of microbial growth in stale or improperly stored food.

Kaur warned to "not consume food left at room temperature for more than two hours", as it can lead to microbiological growth. Sprouts were also flagged as potentially risky in hot weather.

Further, the expert also urged for "high heat cooking method with vegetarian food to be cooked at around 70°C, while non-vegetarian items require temperatures between 70°C and 80°C".

The expert reiterated the need to

• maintain hydration levels of approximately 2.5 to 3 liters per day.
• ensure electrolyte balance,
• take preventive action before body temperature rises.

Even as heatwave conditions continue to intensify across parts of the country, cases of heat-related illnesses are on the rise, leaving many confused between heat stroke and heat exhaustion.

While both are caused by prolonged exposure to high temperatures, their severity, warning signs, and management can differ significantly.

Speaking to HealthandMe, Dr. Naval Vikram, Professor, Department of Medicine, at the AII India Institute of Medical Sciences (AIIMS), explained the key symptoms to watch out for, how to tell the difference between the two conditions, and the simple yet crucial steps individuals can take to protect themselves during extreme heat.

“The general features of a patient with heat stroke are: first, his or her body temperature will be very high. It will not be around normal levels like 104, 105, or 106—it will be significantly elevated. Second, the person may be delirious, confused, or even in a state of unconsciousness or coma. The breathing will also be labored. These are the features of heat stroke,” Dr Vikram said.

On the other hand, a person with heat exhaustion remains conscious, but looks and feels very tired. The individual is also likely to experience

• body ache,
• muscle pain,
• headache,
• muscle cramp,
• body pain or fatigue.

"If this has happened after exposure to heat, it is similar to the feeling one gets after jogging, running, or playing for about half an hour and then feeling exhausted. If that same feeling occurs without doing any such activity, then it is a stage of heat exhaustion, because it is happening due to the heat,” Dr Vikram told HealthandMe.

Who Is More At Risk With Heat-related Problems?

The most vulnerable category for heat-related problems is the extremes of age—the younger children and older adults.

The expert noted that younger children may not be able to express their symptoms completely. They may not be able to tell you exactly what they are feeling.

At the other end, older adults often have multiple health issues—neurological conditions, diabetes, hypertension, and kidney problems.

"So multiple organs may already be affected to some extent. In such situations, if heat-related illness occurs, it becomes difficult to diagnose, especially if they already have neurological problems like confusion or altered behavior," Dr Vikram said.

With existing comorbidities, other organs may already be compromised, so the tipping point towards severity happens very quickly. In contrast, younger individuals generally have greater body reserves.

Therefore, people at the extremes of age are more vulnerable, also because it can sometimes be difficult to recognize and diagnose the condition in them.

How Can One Prevent?

While it may be impossible to avoid rising temperatures, the focus should be on how much you can protect yourself. The expert suggested measures such as:

• Try to avoid exposure to extreme heat as much as possible.

• In case of being exposed, make sure to cover yourself—cover your head and upper body, use an umbrella, stay hydrated, and take breaks in between.

• If you have to work in a hot environment for a couple of hours, take a break in a cooler or temperature-controlled environment for at least half an hour before resuming, rather than continuously working in the heat. These steps can help prevent heat-related problems.

• If symptoms do occur, and it is heat exhaustion, take rest and avoid further activity for some time.

• In more severe cases—if someone shows symptoms like loss of consciousness or very high body temperature—they should be taken to a hospital immediately. Do not try to manage such cases at home.”