Cuts in services, a postcode lottery of availability and delays mean patients are being forced to rely on the public to help raise funds online to buy suitable wheelchairs.
Medics at the British Medical Association's annual representative meeting in Bournemouth unanimously passed a motion calling for users to have "timely access to chairs suitable for their individual conditions".
Dr Hannah Barham-Brown, a junior doctor working in south London, said hundreds of patients were fundraising online for their wheelchairs.
Standard NHS chairs can weigh around 44lb (20kg) and, for some patients, manoeuvring the devices could cause damage, she said.
Dr Barham-Brown, who presented the motion, used crowdfunding to pay for her own wheelchair - which weighs 26.5lb (12kg) and cost around Â£2,000.
The 29-year-old said: "I had to crowdfund my wheelchair halfway through medical school when I was told that it was going to cost around Â£2,000 to get this chair and the NHS were able to offer me a Â£140 voucher or an NHS chair which weighs up to 20 kilos and is very bad, and not remotely ergonomic.
"That was ultimately going to do me more harm than good so my best friend set up a crowdfunding page for me and managed to raise Â£2,000 in 24 hours.
"The standard NHS chair can weigh up to around 20 kilos and it's very poorly designed - it's not remotely ergonomic. NHS chairs are very heavy and very hard to manoeuvre easily.
"In terms of public transport I wouldn't be able to go anywhere in an NHS chair unless there was someone with me helping me. You need to be pushed.
"More and more I'm seeing on social media pleas from people begging for support to buy wheelchairs, not only chairs like this - lightweight self-propelling chairs - but electric chairs.
"The guidelines for getting chairs now are so strict, wheelchair services across the country are being privatised and it's just getting harder and harder to get access.
"Muscular Dystrophy UK recently did a report on this and said that there seems to be a postcode lottery happening around the country.
"For example, my mother is also a wheelchair user with a different condition - she is based up in Newcastle and got her chair fully-funded whereas I got Â£140 towards mine in London.
"That just goes to illustrate how wide a variety of funding options there are across the country and how this is totally unacceptable."
Dr Barham-Brown suffers from Ehlers-Danlos syndrome, which means her joints dislocate easily. Manoeuvring a heavy wheelchair increases the chance of this happening.
She added: "People should not be waiting up to a year, over a year, to get the wheelchair they need. This should be happening in a couple of months maximum. People should not be having to crowdfund for the wheelchairs that they need.
"If they don't have the money and they are not able to contribute to society or to socialise or to have any kind of life then we need to be looking at how they get the chairs that they need."
Samantha Renke,a disabled actress, was forced to crowdfund her electric wheelchair after she was denied one on the NHS.
Earlier this year the disability campaigner, who suffers from brittle bones, turned to the JustGiving website to raise funds for her wheelchair.
She was told she was not eligible for an electric wheelchair through the NHS because she could sufficiently wheel her manual chair in her home.
Other examples of people fundraising for chairs on the GoFundMe site include:
:: A 10-year-old who suffers from a rare genetic muscle disorder, autism and Ehlers-Danlos syndrome - www.gofundme.com/get-oliver-outdoors;
:: A stroke patient who wants a wheelchair so he can get back to work - https://www.gofundme.com/wheelchair-for-andy;
:: An 11-year-old with cerebral palsy - https://www.gofundme.com/help-to-get-electric-wheelchair.