My blood report says neutrophils show a left shift and toxic changes. rouleaux present.is it serious ?

Discuss w/ doctor: This could indicate a serious infection, but that depends more on other symptoms than on the blood count alone -- depending on the site of infection, whether you have Fever, pain, cough, or any number of other symptoms; and the total neutrophil count. There's no way to know with only this information. Discuss ASAP with your doctor.