Purpose: Certain systemic conditions are reported to be risk factors for dry eye disease (DED), but their associations with DED severity are not well studied. We evaluated whether systemic conditions reported to be DED risk factors are associated with severity of DED signs and symptoms., Design: Secondary analysis of data from the Dry Eye Assessment and Management Study, a large-scale multicenter randomized clinical trial of patients with moderate to severe DED., Participants: Five hundred thirty-five adult patients with moderate to severe DED from 27 United States centers., Methods: Patients reported their medical history at baseline. They underwent ocular surface examinations and symptom evaluation using standardized protocols at baseline, 6 months, and 12 months. We analyzed the associations of systemic conditions (a systemic disease or smoking history) reported as potential DED risk factors with the severity of DED signs and symptoms using generalized linear regression models adjusted by age, gender, race, and visit., Main Outcome Measures: Dry eye disease symptoms assessed using the Ocular Surface Disease Index (OSDI), 6 DED signs (tear film break-up time, anesthetized Schirmer testing, corneal fluorescein staining, conjunctival lissamine green staining, tear osmolarity, and meibomian gland dysfunction), and a composite signs severity score from 0 to 1 (1 = most severe)., Results: The mean age was 58 years; 81% were women. More severe DED signs were associated significantly with Sjögren syndrome (mean composite signs severity score 0.52 with disease vs. 0.43 without disease; P < 0.001), facial rosacea (0.47 vs. 0.43; P = 0.002), rheumatoid arthritis (0.47 vs. 0.42; P = 0.002), peripheral artery disease (0.50 vs. 0.43; P < 0.001), and daily smoking history (0.45 vs. 0.43; P = 0.047). Thyroid dysfunction, osteoarthritis, diabetes, irritable bowel syndrome, hypercholesterolemia, hypertension, and hypertriglyceridemia were not associated significantly with DED signs. No conditions were associated significantly with OSDI., Conclusions: In this large, well-characterized cohort of patients with DED assessed under standardized procedures, patients with certain systemic diseases and smoking history showed more severe DED signs compared with patients without the conditions. The profile of significant DED signs varied by systemic condition, reflecting different DED causes. Understanding the systemic conditions and underlying causes that predispose some patients to severe DED can improve management., (Copyright © 2021 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)