One serious element found in A Midsummer Night's Dream concerns the treatment of women. Literary critic Shirley Nelson Garner points out that all throughout the play, Shakespeare points out that the men dominate the women.
One instance we see of male domination is with respect to Demetrius's treatment of Helena. When Helena first chases after him into the woods in pursuit of Hermia and Lysander, Demetrius actually treats her rather abusively, and Helena accepts the abuse rather obediently. Garner points out that Helena's lines encouraging Demetrius's abuse always receive a laugh due to their absurdity, but the lines deal with the much more weighty issue of male dominance:
The more you beat me, I will fawn on you.
Use me but as your spaniel, spurn me, strike me,
Neglect me, lose me; only give me leave,
Unworthy as I am, to follow you. (II.i.207-211)
In addition, Demetrius's own lines delivered to Helena threaten her with phyiscal violence, even rape:
You do impeach your modesy too much
To leave the city and commit yourself
Into the hands of one that loves you not. (218-220)
In addition to Demetrius's treatment of Helena, we see male domination in Oberon's treatment of Titania. We even see Titania respond with obedience once Oberon has lifted love spell he has enchanted her with. Plus, we see the issue of male dominance portrayed in the fact that Helena and Hermia fall completely silent in the fifth act, immediately after their weddings. Garner points out that their silence helps to characterize them as accepting their new roles of being obedient, silent wives.
Hence, we see that while A Midsummer Night's Dream is a comedy, it is peppered with weightier social issues and injustices.