The door of Rehana Khan’s sixth-floor flat is as far as she ventures during the day.

On most days, she barely leaves her bed.

The city outside is too chaotic and overwhelming for her.Khan, 57, moved to Bangladesh’s capital, Dhaka, a year ago, after her husband died.

She lives with her only son and his wife, who were worried about her being alone in a village in the north-eastern district of Sylhet.Many of Bangladesh’s emerging middle class face the same problem: tied to Dhaka for work, they struggle to balance city lives with caring for parents, who then end up having to follow their children to the metropolis, a place they can find inhospitable and strange.Quick GuideA common conditionShowThe human toll of non-communicable diseases (NCDs) is huge and rising.

These illnesses end the lives of approximately 41 million of the 56 million people who die every year – and three quarters of them are in the developing world.NCDs are simply that; unlike, say, a virus, you can’t catch them.

Instead, they are caused by a combination of genetic, physiological, environmental and behavioural factors.

The main types are cancers, chronic respiratory illnesses, diabetes and cardiovascular disease – heart attacks and stroke.

Approximately 80% are preventable, and all are on the rise, spreading inexorably around the world as ageing populations and lifestyles pushed by economic growth and urbanisation make being unhealthy a global phenomenon.NCDs, once seen as illnesses of the wealthy, now have a grip on the poor.

Disease, disability and death are perfectly designed to create and widen inequality – and being poor makes it less likely you will be diagnosed accurately or treated.Investment in tackling these common and chronic conditions that kill 71% of us is incredibly low, while the cost to families, economies and communities is staggeringly high.In low-income countries NCDs – typically slow and debilitating illnesses – are seeing a fraction of the money needed being invested or donated.

Attention remains focused on the threats from communicable diseases, yet cancer death rates have long sped past the death toll from malaria, TB and HIV/Aids combined.'A common condition' is a Guardian series reporting on NCDs in the developing world: their prevalence, the solutions, the causes and consequences, telling the stories of people living with these illnesses.Tracy McVeigh, editorThank you for your feedback.Doctors recommended that Khan walks for 45 minutes a day to manage her diabetes and high cholesterol but she is scared to venture out.

In common with many of the city’s elderly people who live with non-communicable diseases such as diabetes, heart conditions and asthma, she finds Dhaka’s dangerous roads and lack of green spaces intimidating.View image in fullscreenRehana Khan outside the door to her sixth-floor flat, which is the limit of her world most days.

Photograph: Abir Abdullah/The Guardian“The traffic, the pollution, the noise … it disturbs me.

So I don’t go out alone.

The whole day is spent inside,” says Khan.“I don’t like it here.

There’s nothing here for me.

My son and his wife leave for the office early in the morning and it’s just me.

I have no friends, no husband.

I don’t have much connection with the neighbours like I do in the village.

But I’m forced to stay here because I have no other option.”She waits for the weekend, when her son tries to make time to take her out.View image in fullscreenPedestrians are forced to walk among the traffic while roadworks are undertaken in Dhanmondi, Dhaka, Bangladesh.

Photograph: Abir Abdullah/The GuardianDhaka’s population grows by an estimated half a million people every year and has struggled to expand in a way that caters for all.

Younger generations come for the jobs, bringing their parents to ensure they are cared for but day-to-day life can be a challenge in a country where 70% of deaths were caused by NCDs in 2019.For elderly and less mobile people, uneven or nonexistent sidewalks make navigating the city difficult.

The situation is not helped by traders setting up businesses on the sides of busy roads, a lack of pedestrian crossings and buses which rarely stop long enough for older people to board.I feel stressed when I go outside, all the cars and the rickshaws.

All the trafficMohammed Bodi-Uz Zaman, 85Traffic rules are flouted, including by rickshaws that cut through pedestrian areas and race the wrong way down certain streets.“I used to walk around by myself but now I don’t feel safe any more,” says Mohammed Bodi-Uz Zaman, 85.

“To stay in the house is safer than outside because of the pollution.

There is no footpath, there are hawkers blocking the way and rickshaws everywhere.”Zaman spent decades working at the Bangladesh Agricultural University in Mymensingh but settled in Dhaka after retiring on the insistence of his family, who did not want him to stay alone in his village, about seven miles from Dhaka.Zaman occasionally goes to the village to visit his relatives but much of his day is spent in his son’s flat and the balcony where he sits reading the newspaper.View image in fullscreenZaman spends his time reading on his balcony but misses the freedom he enjoyed in the countryside.

Photograph: Abir Abdullah/The Guardian“I feel stressed when I go outside, all the cars and the rickshaws.

All the traffic – it feels like any time it can hit me,” says Zaman.He lives with high blood pressure, chronic breathing problems and allergies that mean that he would benefit from regular walks.

But the pollution and dangerous streets keep him indoors.“It’s more comfortable in the village, I feel better there, I feel joy when I see my relatives, but I’m bound to the city.”Most neighbourhoods have very little access to green spaces, which covered 47% of the city in 1992 but that fell to 16% in 2022, according to a study by researchers at Dhaka’s Jahangirnagar University.Debra Efroymson, who runs the Institute of Wellbeing, a Bangladeshi NGO, says the city needs to be rethought, with the priority taken away from cars to improve residents’ quality of life.She says she has seen elderly people choose to go for walks in car parks even when a public park is nearby because they fear crossing the road.View image in fullscreenOlder residents find navigating busy streets, often crowded with street traders’ stalls, challenging.

Photograph: Abir Abdullah/The Guardian“The main concern of policymakers seems to be to accommodate the cars, so there’s a lot of talk about where the car is going to park and how the car is going to move through the city.

What is lacking is any concern about people,” says Efroymson.Efroymson spent the past winter in Dhaka during a period of heavy air pollution, including a day when it was declared the most polluted city in the world.

She suggests a state of emergency should be imposed in Dhaka because of pollution, and recommends the city has car free days, as well as better planning “so people aren’t dying from breathing”.“If you want a dignified life for all people – the elderly, people with mobility limitations or other disabilities – you have to have a quality environment where people can walk, move about safely and access the existing public spaces.”.

This article first appeared/also appeared in theguardian.com