, FIRST AID FOR
THE®
USMLE
STEP 1
2025
TAO LE, MD, MHS VIKAS BHUSHAN, MD
Founder, ScholarRx Founder, First Aid for the USMLE Step 1
Associate Clinical Professor, Department of Medicine Boracay, Philippines
University of Louisville School of Medicine
ANUP CHALISE, MBBS, MS, MRCSEd JAIMIE ROGNER, MD, MPH
Registrar, General and Colorectal Surgery Resident, Department of Psychiatry
North Middlesex University Hospital, London NewYork-Presbyterian/Weill Cornell Medical Center
CAROLINA CABAN RIVERA CAROLINE COLEMAN, MD
MD/PhD Candidate, Class of 2025 Adjunct Professor, Department of Medicine
Lewis Katz School of Medicine at Temple University Emory University School of Medicine
KIMBERLY KALLIANOS, MD SEAN EVANS, MD
Assistant Professor, Department of Radiology and Biomedical Imaging Resident, Department of Medicine
University of California, San Francisco School of Medicine Emory University School of Medicine
FAS1_2025_00_Frontmatter.indd 1 12/19/24 3:06 PM
, First Aid for the® USMLE Step 1 2025: A Student-to-Student Guide
Copyright © 2025 by Tao Le and Vikas Bhushan. All rights reserved. Printed in the United States of America. Except as
permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distrib-
uted in any form or by any means, or stored in a data base or retrieval system, without the prior written permission of
the publisher.
Previous editions copyright © 1991 through 2024 by Tao Le and Vikas Bhushan. First edition copyright © 1990, 1989
by Vikas Bhushan, Je!rey Hansen, and Edward Hon.
Photo and line art credits for this book begin on page 755 and are considered an extension of this copyright page.
Portions of this book identi"ed with the symbol are copyright © USMLE-Rx.com (MedIQ Learning, LLC).
Portions of this book identi"ed with the symbol are copyright © Dr. Richard Usatine.
Portions of this book identi"ed with the symbol are under license from other third parties. Please refer to page 755
for a complete list of those image source attribution notices.
First Aid for the® is a registered trademark of McGraw Hill.
$PrintCode
ISBN 978-1-266-34646-0
MHID 1-266-34646-5
ISSN 1532-6020
Notice
Medicine is an ever-changing science. As new research and clinical experience broaden our knowledge,
changes in treatment and drug therapy are required. The authors and the publisher of this work have checked
with sources believed to be reliable in their e!orts to provide information that is complete and generally in
accord with the standards accepted at the time of publication. However, in view of the possibility of human
error or changes in medical sciences, neither the authors nor the publisher nor any other party who has been
involved in the preparation or publication of this work warrants that the information contained herein is in
every respect accurate or complete, and they disclaim all responsibility for any errors or omissions or for the
results obtained from use of the information contained in this work. Readers are encouraged to confirm the
information contained herein with other sources. For example and in particular, readers are advised to check
the product information sheet included in the package of each drug they plan to administer to be certain
that the information contained in this work is accurate and that changes have not been made in the recom-
mended dose or in the contraindications for administration. This recommendation is of particular importance
in connection with new or infrequently used drugs.
This book was set in Electra LT Std by GW Inc.
The editors were Bob Boehringer and Peter J. Boyle.
Project management was provided by GW Inc.
The production supervisor was Je!rey Herzich.
LSC Communications was printer and binder.
This book is printed on acid-free paper.
International Edition ISBN 1-266-25125-2; MHID 1-266-25125-1.
Copyright © 2025. Exclusive rights by McGraw Hill for manufacture and export. This book cannot be reexported from
the country to which it is consigned by McGraw Hill. The International Edition is not available in North America.
McGraw Hill books are available at special quantity discounts to use as premiums and sales promotions,
or for use in corporate training programs. To contact a representative please visit the Contact Us pages at
www.mhprofessional.com.
FAS1_2025_00_Frontmatter.indd 2 12/19/24 3:06 PM
, Dedication
To medical students and physicians worldwide for
collaborating to improve medical education and practice.
FAS1_2025_00_Frontmatter.indd 3 12/19/24 3:06 PM
THE®
USMLE
STEP 1
2025
TAO LE, MD, MHS VIKAS BHUSHAN, MD
Founder, ScholarRx Founder, First Aid for the USMLE Step 1
Associate Clinical Professor, Department of Medicine Boracay, Philippines
University of Louisville School of Medicine
ANUP CHALISE, MBBS, MS, MRCSEd JAIMIE ROGNER, MD, MPH
Registrar, General and Colorectal Surgery Resident, Department of Psychiatry
North Middlesex University Hospital, London NewYork-Presbyterian/Weill Cornell Medical Center
CAROLINA CABAN RIVERA CAROLINE COLEMAN, MD
MD/PhD Candidate, Class of 2025 Adjunct Professor, Department of Medicine
Lewis Katz School of Medicine at Temple University Emory University School of Medicine
KIMBERLY KALLIANOS, MD SEAN EVANS, MD
Assistant Professor, Department of Radiology and Biomedical Imaging Resident, Department of Medicine
University of California, San Francisco School of Medicine Emory University School of Medicine
FAS1_2025_00_Frontmatter.indd 1 12/19/24 3:06 PM
, First Aid for the® USMLE Step 1 2025: A Student-to-Student Guide
Copyright © 2025 by Tao Le and Vikas Bhushan. All rights reserved. Printed in the United States of America. Except as
permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distrib-
uted in any form or by any means, or stored in a data base or retrieval system, without the prior written permission of
the publisher.
Previous editions copyright © 1991 through 2024 by Tao Le and Vikas Bhushan. First edition copyright © 1990, 1989
by Vikas Bhushan, Je!rey Hansen, and Edward Hon.
Photo and line art credits for this book begin on page 755 and are considered an extension of this copyright page.
Portions of this book identi"ed with the symbol are copyright © USMLE-Rx.com (MedIQ Learning, LLC).
Portions of this book identi"ed with the symbol are copyright © Dr. Richard Usatine.
Portions of this book identi"ed with the symbol are under license from other third parties. Please refer to page 755
for a complete list of those image source attribution notices.
First Aid for the® is a registered trademark of McGraw Hill.
$PrintCode
ISBN 978-1-266-34646-0
MHID 1-266-34646-5
ISSN 1532-6020
Notice
Medicine is an ever-changing science. As new research and clinical experience broaden our knowledge,
changes in treatment and drug therapy are required. The authors and the publisher of this work have checked
with sources believed to be reliable in their e!orts to provide information that is complete and generally in
accord with the standards accepted at the time of publication. However, in view of the possibility of human
error or changes in medical sciences, neither the authors nor the publisher nor any other party who has been
involved in the preparation or publication of this work warrants that the information contained herein is in
every respect accurate or complete, and they disclaim all responsibility for any errors or omissions or for the
results obtained from use of the information contained in this work. Readers are encouraged to confirm the
information contained herein with other sources. For example and in particular, readers are advised to check
the product information sheet included in the package of each drug they plan to administer to be certain
that the information contained in this work is accurate and that changes have not been made in the recom-
mended dose or in the contraindications for administration. This recommendation is of particular importance
in connection with new or infrequently used drugs.
This book was set in Electra LT Std by GW Inc.
The editors were Bob Boehringer and Peter J. Boyle.
Project management was provided by GW Inc.
The production supervisor was Je!rey Herzich.
LSC Communications was printer and binder.
This book is printed on acid-free paper.
International Edition ISBN 1-266-25125-2; MHID 1-266-25125-1.
Copyright © 2025. Exclusive rights by McGraw Hill for manufacture and export. This book cannot be reexported from
the country to which it is consigned by McGraw Hill. The International Edition is not available in North America.
McGraw Hill books are available at special quantity discounts to use as premiums and sales promotions,
or for use in corporate training programs. To contact a representative please visit the Contact Us pages at
www.mhprofessional.com.
FAS1_2025_00_Frontmatter.indd 2 12/19/24 3:06 PM
, Dedication
To medical students and physicians worldwide for
collaborating to improve medical education and practice.
FAS1_2025_00_Frontmatter.indd 3 12/19/24 3:06 PM