President Barack Obama certainly has a demanding job, and over the years, his changing physical appearance has been the subject of many discussions. It is without question that being the president of the United States is one of the toughest jobs in the world. From traveling all over the world to build rapport with other leaders, to working toward policy change, a job like that causes serious stress, and can leave one with much grayer hair. From additional wrinkles on his face to gray hair, Obama has certainly dealt with a transformation. And this is common among presidents.

“You look at the picture when they’re inaugurated and four years later, they’re visibly older,” Connie Mariano, White House physician from 1992 to 2001, told The Washington Post in 2013. “It’s like they went in a time machine and fast-forwarded eight years in the span of four years.” 

Prior to being President, Obama was a member of the Illinois Senate from the 13th district on Chicago's Southeast Side from 1996 to 2004. He was elected to the U.S. Senate in 2004, before being elected president in 2008.

 Let’s take a look back at how his appearance has changed over the past decade.

Barack Obama in 2004

Barack Obama In 2004 Barack Obama, candidate for a Senate seat in Illinois and one of the keynote speakers of the 2004 Democratic National Convention, addresses delegates during the second night of the event in Boston, July 27, 2004. Photo: Reuters

Barack Obama in 2005

Barack Obama in 2005 United States Senator Barack Obama (D-Illinois) poses for photographers at the 36th NAACP Image Awards in Los Angeles, March 19, 2005. Photo: Reuters

Barack Obama in 2006 Barack Obama in 2006 Senator Barack Obama, R, (D-IL) listens to proceedings during a Senate Rules Committee hearing on overhauling lobbying on Capitol Hill in Washington, February 8, 2006 Photo: Reuters

Barack Obama in 2007

Barack Obama in 2008

Barack Obama Democratic presidential candidate U.S. Senator Barack Obama (D-IL) sits during the Democratic candidate debate at Saint Anselm College in Manchester, New Hampshire January 5, 2008. Photo: Reuters

Barack Obama in 2009

Barack Obama U.S. President George W. Bush greets U.S. President-elect Barack Obama (L) on the North Portico of the White House in Washington, January 20, 2009. Photo: Reuters

Barack Obama in 2010

Barack Obama U.S. President Barack Obama delivers remarks on job creation and the economy at Oasis Mechanical Contractors Inc, a small in business in Lanham, Maryland, February 5, 2010. Photo: Reuters

Barack Obama in 2011

Barack Obama U.S. President Barack Obama pauses as he addresses the crowd assembled at the "Together We Thrive: Tucson and America" event held to support and remember the victims of the mass shooting, at the University of Arizona in Tucson, Arizona, January 12, 2011. Photo: Reuters

Barack Obama in 2012

Barack Obama U.S. President Barack Obama holds a news conference from the White House Press Briefing Room in Washington, March 6, 2012. Photo: Reuters

Barack Obama in 2013

Barack Obama U.S. President Barack Obama speaks at a news conference with Israel's Prime Minister Benjamin Netanyahu at the Prime Minister's residence in Jerusalem, March 20, 2013. Photo: Reuters

Barack Obama in 2014

Barack Obama U.S. President Barack Obama talks about the Affordable Care Act in the Brady Press Briefing Room at the White House in Washington. Photo: Reuters