( ( In ( people ( who ( have ( ( large ( varicose veins ) ) ( in ( their legs ) ) ) ) ) ) ) ( , ( ( ( ( ( ( the valves ) ( in ( their veins ) ) ) ( ( are not ) ( closing properly ) ) ) and ) ( ( some ( of ( their blood ) ) ) ( is ( ( ( pooling ( in ( their legs ) ) ) ( rather than ) ) ( ( traveling back ) ( to ( the heart ) ) ) ) ) ) ) . ) ) )
(ROOT (S (PP (IN In) (NP (NP (NNS people)) (SBAR (WHNP (WP who)) (S (VP (VBP have) (NP (NP (JJ large) (NN varicose) (NNS veins)) (PP (IN in) (NP (PRP$ their) (NNS legs))))))))) (, ,) (S (NP (NP (DT the) (NNS valves)) (PP (IN in) (NP (PRP$ their) (NNS veins)))) (VP (VBP are) (RB not) (VP (VBG closing) (ADVP (RB properly))))) (CC and) (S (NP (NP (DT some)) (PP (IN of) (NP (PRP$ their) (NN blood)))) (VP (VBZ is) (S (VP (VP (VBG pooling) (PP (IN in) (NP (PRP$ their) (NNS legs)))) (CONJP (RB rather) (IN than)) (VP (VBG traveling) (ADVP (RB back)) (PP (TO to) (NP (DT the) (NN heart)))))))) (. .)))
In people who have large varicose veins in their legs, the valves in their veins are not closing properly and some of their blood is pooling in their legs rather than traveling back to the heart.
(ROOT (S (NP (JJ Varicose) (NNS veins)) (VP (VBP are) (NP (NP (NNS veins)) (SBAR (WHNP (WDT that)) (S (VP (VBP become) (S (VP (VBG enlarged) (SBAR (IN because) (S (NP (DT the) (NNS valves)) (ADVP (RB no) (RB longer)) (VP (VB close) (ADVP (RB properly)))))))))))) (. .)))