Shakespeare portrays a troubled relationship between Gertrude and Hamlet. As the play opens, Hamlet is deeply distressed that his mother so quickly remarried her brother-in-law after her husband's death. He can hardly believe Gertrude was willing to settle for someone who, in Hamlet's opinion, was so much lesser than his late father. Hamlet calls his father a Hyperion or sun god, while he calls Claudius a satyr, a lustful half human, half animal figure.
The mother and son, however, love each other. Gertrude has a great deal of concern over her son's behavior, which makes no sense to her. Claudius knows he has to tread carefully around the subject of Hamlet, a person he would simply like to get rid of, because Gertrude cares about him so much. Gertrude would like to see Hamlet settle down and marry Ophelia.
Hamlet, however, is angry and disillusioned about women in general because of what he considers Gertrude's betrayal in marrying Claudius. When he finally confronts her, she admits they married for convenience. At the same time, she is terrified that Hamlet, in his frenzied state, might kill her.
Hamlet's love for his mother shows, however, at the end of the play. He has been indecisive all along about killing Claudius, but when he realizes Claudius has allowed Gertrude to drink from the poisoned cup, he kills his uncle.