Lindsay Lohan believes getting arrested is bad for her health ... 'cause she's telling friends the stress from her NYC bust aggravated her pre-existing pneumonia so badly, she had to be hospitalized.
We broke the story .. Lohan was rushed to the emergency room in NYC Sunday night with a lung infection ... but was released a short time later.
Now, Lindsay's telling friends the arrest caused her so much anxiety, it landed her in the hospital -- exacerbating the "walking pneumonia" she's been suffering from the last few weeks.
That's right, Lindsay is blaming stress for her damaged lungs ... Lindsay, the infamous chain smoker who blew through 49 packs of cigarettes in 47 days while she stayed at the Chateau Marmont this summer.
Makes total sense.