She is the youngest child and only daughter of Mahmuda Nahar (Ruby), a musician and teacher, and Nazmee Jahan Chowdhury, an executive at James Finlay Bangladesh.

[26] Nazreen was trained in classical music and dance as a young child but discontinued practice after her mother, who was also her first teacher, left the family.

In high school, Nazreen competed in volleyball and handball and was under detention for a long time, as a result of bunking academic classes to play.

[29] She worked in three big productions as an assistant Director to Azad Abul Kalam and alongside Rahul Anand and several other members of the band Joler Gaan.

For post-graduate studies, Nazreen was a distant scholar at Samye Ling College of Scotland and pursued a Nangi Shedra in Indo-Tibetan Buddhism.

[38] She is part of the Save Sundarbans movement, and was a critical voice to pressure the GOB and other concerned bodies in cleaning up efforts following the disastrous oil-spill of 2013/4.

However, when the funding for one of CARE's long-time projects ceased, Nazreen believed that it was crucial for the Bangladeshi people to establish their aid organizations, rather than rely solely on foreign assistance.

While working in Tibet to combat human rights violations by the Chinese government, Nazreen discovered her interest in mountaineering.

[13] After finishing climbing the seven summits, Nazreen started her own foundation Ösel Foundation, which she describes as an “educational institute set in the outdoors, which integrates the latest scientific findings about the development of the mind and combines it with mindfulness techniques and training in nature to empower adolescent girls.”[26] Her work with Tibetan human rights took her to Dharamsala, Himachal Pradesh, the exiled-capital of the Tibetans, where she lived for several years in her early twenties.

[30][40] Nazreen was part of the international movement for greater freedom and better human rights conditions inside Tibet and some high-profile protests and uprisings, leading up to the 2008 Beijing Olympic Games, including the March to Tibet protest in solidarity with 2008 Tibetan Uprising and several concerts and other events throughout the globe.

[41] In 2009, with pressure from the Chinese Embassy in Bangladesh, her photography exhibition titled "Into Exile: Tibet 1949-2009" in partnership with DRIK, was shut down in Dhaka.

The exhibition was still shown online while riot-geared police barricaded the premises and audience waited in the streets and consequently, she was intimidated and harassed for months by authorities and intelligence in her country.

Nazreen managed to get a permit the following day and flew a plane carrying a message that had an image of Shahidul reading “#FreeShahidulAlam”, as well as a text banner saying “Free Our Teachers #Bangladesh #UNGA” in New York skyline, traversing the Statue of Liberty, while the United Nations General Assembly was in effect.

[44][45][46][47] She made a direct push from camp 3, skipping camp 4 and reached the summit at 8:55 AM local Gilgit-Baltistan time, with Mingma Sherpa and descended the mountain in a daring two-day push, with Nirmal Purja, popularly known as Nimsdai, the record shattering mountaineer and Gurkha soldier behind the movie 14 Peaks: Nothing Is Impossible.

[49] This was a historic expedition, given that Bangladesh fought for its independence from Pakistan only fifty years ago, and was received with admiration and support from both countries.

[57] Many other notable individuals, including Sir Fazle Hasan Abed, Professor Muhammad Yunus, and the 14th Dalai Lama, were her outspoken supporters throughout the campaign.

[68] Patrick Morrow, the first person in the world to have climbed the highest peaks of all seven continents (in accordance with the Messner list)[69] has overseen her training for seven summits.

Nazreen has had deep connections with many master teachers in the Tibetan traditions spanning across Tibet, Nepal and India and was given the name Karma Ösel Lhamo by the Karmapa, which roughly translates as Goddess of luminous actions.

[28] A long-time supporter of Tibet, Nazreen is close friends with the 14th Dalai Lama, Tenzin Gyatso, Dilgo Khyentse Rinpoche and the 17th Karmapa Ogyen Trinley Dorje.

[26] Nazreen openly discusses accounts of dealing with depression and trauma as a child following her parents divorce that made her homeless as a result.

She credits such struggle at early life for giving her "abilities to bounce back after adversities and greet change and difficulties as an opportunity to welcome greater self-reflection, learning, and growth.

Nazreen is often quoted in TV and other media requesting against labeling her mountaineering expeditions as a "conquering" feat due to its colonial and patriarchal nature.