Hospital sources said that she was being treated with anti-coagulants and kept under constant monitoring. The doctors would decide if further medical action was required, Deputy Assistant Secretary Philippe Reines said.
Clinton, the wife of former American President Bill Clinton, was hit by a stomach virus after a whirlwind trip to Europe at the beginning of this month. She had suffered from severe dehydration and fainted and fell at home, which caused the concussion. She wasn't hospitalised then.
She had to cancel trips to North Africa and the United Arab Emirates and also the testimony before the Congress at hearings on the dreaded attack on the US consulate in Benghazi in Libya, which resulted in the death of the US Ambassador to that country.
Clinton, 65, was treated by two teams of doctors following her fall. She was on an IV drip following the concussion and was also undergoing treatment for the pain that was caused by the collapse.
Clinton has been spending a very hectic life since taking office four years ago. She visited 112 countries and spent some 400 days in a plane since 2008.
The Democrat politician is expected to contest the presidential election in 2016.