Asthma patients have to take extra care in the city's smoggy conditions that have been prevailing for the past few days, a doctor at Max Hospital said Saturday.
"Heavy smog in the city is causing respiratory tract infections and other health problems and people are advised to wear an air filter mask when outside," he added.
The fall in temperature is also leading to headaches, mood swings and depression.
A senior scientist from Delhi Pollution Control Committee said that major cause of this smoggy weather is due to lower temperature, lower wind speed and pollutants not getting dispersed.
He said that air pollution in the city is also the major reason behind this weather and cyclone Nilam is also effecting Delhi's weather.
Senior scientist R.M. Bhardwaj of Central Pollution Control Board said: "Increasing number of vehicles in the city is one of the major factors for rising air pollution."
An official of the Indian Meteorological Department (IMD) said that winds are very slow and dust particles in the air are causing smog.
Asthma patient Tina Sharma, a resident of R.K. Puram here, said: "Haze is the worst time for asthma patients. When I step out I carry my nebuliser (inhaler) with me," she said.
Aarti Vij, 33, a mother of a five-year-old, said: "Smog and pollutants are suffocating, particularly for asthma patients. This is the worst time for my child. I have to keep his nebuliser handy."