In his grief for Lady Macbeth, Macbeth reminds us for a moment of Macduff. Compare and contrast the emotion and reactions of both men to the news that their wives are dead in Macbeth.
Macduff, in Shakespeare's Macbeth, serves as a foil to Macbeth in their reactions to grief, as well as in numerous other ways, which I won't mention here.
Macduff does not hide his grief. The opportunistic Malcolm tries to immediately use the death of Macduff's family to motivate Macduff to go after Macbeth. Malcolm mildly plays the macho card, appeals to Macduff's aggressive nature. But Macduff is not afraid to show emotion. He must suffer and hurt like a man, he says, before he can avenge like a man.
But his loss and his sorrow do not lead Macduff into despair. Instead, they drive him to vengeance, demonstrating what a mistake it was for Macbeth to order the murders of Macduff's family members.
Macbeth, on the other hand, is driven to despair by the news of his wife's death. In his "Tomorrow" speech (Act 5.5), he philosophically slips into nihilism, seeing his existence as meaningless. Lady Macbeth's death brings out the rational side of Macbeth, the side of him that knows the witches' predictions are too good to be true. And despair is the result.
Macbeth recovers from his despair, however, and dies a noble death. He faces his enemy head on and battles to the death. But his reaction to the news of his wife's death is not equal to Macduff's ideal handling of his loss.